Use ex_doc admonition blocks when possible

lib/elixir/lib/application.ex

@@ -54,12 +54,16 @@ defmodule Application do
   You can also change the application environment dynamically by using functions
   such as `put_env/3` and `delete_env/2`.
 
-  > Note: The config files `config/config.exs` and `config/runtime.exs`
+  > #### Environment in Libraries {: .tip}
+  >
+  > The config files `config/config.exs` and `config/runtime.exs`
   > are rarely used by libraries. Libraries typically define their environment
-  > in the `def application` function of their `mix.exs`. Configuration files
+  > in the `application/0` function of their `mix.exs`. Configuration files
   > are rather used by applications to configure their libraries.
 
-  > Note: Each application is responsible for its own environment. Do not
+  > #### Reading the Environment of Other Applications {: .warning}
+  >
+  > Each application is responsible for its own environment. Do not
   > use the functions in this module for directly accessing or modifying
   > the environment of other applications. Whenever you change the application
   > environment, Elixir's build tool will only recompile the files that

lib/elixir/lib/kernel.ex

@@ -5540,7 +5540,9 @@ defmodule Kernel do
   As seen as in the example above, `super` can be used to call the default
   implementation.
 
-  > Note: use `defoverridable` with care. If you need to define multiple modules
+  > #### Disclaimer {: .tip}
+  >
+  > Use `defoverridable` with care. If you need to define multiple modules
   > with the same behaviour, it may be best to move the default implementation
   > to the caller, and check if a callback exists via `Code.ensure_loaded?/1` and
   > `function_exported?/3`.
@@ -5722,7 +5724,9 @@ defmodule Kernel do
   the usual macro rules apply, and its return value should be quoted code
   that is then inserted where `use/2` is called.
 
-  > Note: `use MyModule` works as a code injection point in the caller.
+  > #### Code Injection {: .warning}
+  >
+  > `use MyModule` works as a **code-injection point** in the caller.
   > Given the caller of `use MyModule` has little control over how the
   > code is injected, `use/2` should be used with care. If you can,
   > avoid use in favor of `import/2` or `alias/2` whenever possible.

lib/elixir/lib/macro.ex

@@ -56,7 +56,9 @@ defmodule Macro do
   To learn more about Elixir's AST and how to build them programmatically,
   see `quote/2`.
 
-  > Note: the functions in this module do not evaluate code. In fact,
+  > #### Evaluating Code {: .tip}
+  >
+  > The functions in this module do not evaluate code. In fact,
   > evaluating code from macros is often an anti-pattern. For code
   > evaluation, see the `Code` module.
 

lib/elixir/lib/map.ex

@@ -52,8 +52,10 @@ defmodule Map do
       map.non_existing_key
       ** (KeyError) key :non_existing_key not found in: %{baz: "bong", foo: "bar"}
 
-  > Note: do not add parens when accessing fields, such as in `data.key()`.
-  > If parenthesis are used, Elixir will expect `data` to be an atom representing
+  > #### Avoid Parentheses {: .warning}
+  >
+  > Do not add parentheses when accessing fields, such as in `data.key()`.
+  > If parentheses are used, Elixir will expect `data` to be an atom representing
   > a module and attempt to call the *function* `key/0` in it.
 
   The two syntaxes for accessing keys reveal the dual nature of maps. The `map[key]`
@@ -1078,7 +1080,9 @@ defmodule Map do
   See also `reject/2` which discards all elements where the
   function returns a truthy value.
 
-  > Note: if you find yourself doing multiple calls to `Map.filter/2`
+  > #### Performance Considerations {: .tip}
+  >
+  > If you find yourself doing multiple calls to `Map.filter/2`
   > and `Map.reject/2` in a pipeline, it is likely more efficient
   > to use `Enum.map/2` and `Enum.filter/2` instead and convert to
   > a map at the end using `Map.new/1`.

lib/elixir/lib/map_set.ex

@@ -332,10 +332,12 @@ defmodule MapSet do
   Also see `reject/2` which discards all elements where the function returns
   a truthy value.
 
-  > Note: if you find yourself doing multiple calls to `MapSet.filter/2`
+  > #### Performance Considerations {: .tip}
+  >
+  > If you find yourself doing multiple calls to `MapSet.filter/2`
   > and `MapSet.reject/2` in a pipeline, it is likely more efficient
   > to use `Enum.map/2` and `Enum.filter/2` instead and convert to
-  > a map at the end using `Map.new/1`.
+  > a map at the end using `MapSet.new/1`.
 
   ## Examples
 

lib/elixir/lib/string.ex

@@ -2484,7 +2484,9 @@ defmodule String do
   function will search if any of the strings in `contents`
   are part of `string`.
 
-  > Note: if you want to check if `string` is listed in `contents`,
+  > #### Searching For a String In a List {: .tip}
+  >
+  > If you want to check if `string` is listed in `contents`,
   > where `contents` is a list, use `Enum.member?(contents, string)`
   > instead.
 

lib/elixir/lib/supervisor.ex

@@ -20,7 +20,9 @@ defmodule Supervisor do
   a generic server, that keeps a counter. Other processes can then send
   messages to this process to read the counter and bump its value.
 
-  > Note: in practice you would not define a counter as a GenServer. Instead,
+  > #### Disclaimer {: .neutral}
+  >
+  > In practice you would not define a counter as a GenServer. Instead,
   > if you need a counter, you would pass it around as inputs and outputs to
   > the functions that need it. The reason we picked a counter in this example
   > is due to its simplicity, as it allows us to focus on how supervisors work.

lib/elixir/lib/uri.ex

@@ -680,8 +680,10 @@ defmodule URI do
   If a `%URI{}` struct is given to this function, this function returns it
   unmodified.
 
-  > Note: this function sets the field :authority for backwards
-  > compatibility reasons but it is deprecated.
+  > #### `:authority` Field {: .info}
+  >
+  > This function sets the field `:authority` for backwards-compatibility reasons
+  > but it is deprecated.
 
   ## Examples
 

lib/mix/lib/mix.ex

@@ -148,7 +148,9 @@ defmodule Mix do
   the application environment. On this section, we will focus on how to configure
   it at two distinct moments: build-time and runtime.
 
-  > Note: The application environment is discouraged for libraries. See Elixir's
+  > #### Avoiding the Application Environment {: .warning}
+  >
+  > The application environment is discouraged for libraries. See Elixir's
   > [Library Guidelines](https://hexdocs.pm/elixir/library-guidelines.html) for
   > more information.
 

lib/mix/lib/mix/tasks/escript.build.ex

@@ -36,7 +36,9 @@ defmodule Mix.Tasks.Escript.Build do
   the compiled `.beam` files to reduce the size of the escript.
   If this is not desired, check the `:strip_beams` option.
 
-  > Note: escripts do not support projects and dependencies
+  > #### `priv` Directory Support {: .warning}
+  >
+  > escripts do not support projects and dependencies
   > that need to store or read artifacts from the priv directory.
 
   ## Command line options