feat(docs): More detailed configuration docs

book/src/guide/configuration.md

@@ -1,6 +1,34 @@
 # Configuration
 
-Orogene currently uses toml files for (persistent) configuration. Soon, this
-will be replaced with a [kdl](https://kdl.dev)-based configs.
+## Specifying Configurations
 
-Until then, this page will stay mostly blank.
+Orogene configuration happens in three different ways, in order of precedence:
+
+1. Direct command line flags (`--foo blah`), which can be negated (`--no-foo`)
+2. [KDL](https://kdl.dev) [configuration file(s)](#configuration-files) (`oro.kdl`)
+3. Environment variables, prefixed by `oro_config_` (`oro_config_foo=blah`)
+
+## Configuration Files
+
+There are three possible configuration file locations:
+
+1. `oro.kdl`, located in the root of the current project.
+2. `oro.kdl`, located in a [system-dependent
+   location](https://docs.rs/directories/latest/directories/struct.ProjectDirs.html#method.config_dir)
+3. Any file specified by using the global `--config FILE` CLI option. When
+   this option is specified, neither of the other configuration files are
+   loaded, and file-based configuration happens entirely off the given file.
+   Environment variables and command line options will still be loaded
+   normally.
+
+All files files use [KDL](https://kdl.dev) as their configuration language.
+Key/value options are specified using `node-name "value"` format. For example,
+`foo "bar"` would be the equivalent of `--foo bar`. For boolean operations,
+use `foo true` and `foo false`. Negations (`no-foo`) are not supported.
+
+## Available Options
+
+All available options for individual commands are available by doing `oro
+<subcommand> --help`, or by visiting the individual commands' documentation
+pages on this site. "Global Options" can potentially be used across all
+commands and have a shared meaning.