feat: add require-inexact-type rule (#408)

* feat: add require-inexact-type rule

* docs: generate docs

.README/README.md

@@ -173,7 +173,9 @@ When `true`, only checks files with a [`@flow` annotation](http://flowtype.org/d
 {"gitdown": "include", "file": "./rules/object-type-delimiter.md"}
 {"gitdown": "include", "file": "./rules/require-compound-type-alias.md"}
 {"gitdown": "include", "file": "./rules/require-exact-type.md"}
+{"gitdown": "include", "file": "./rules/require-inexact-type.md"}
 {"gitdown": "include", "file": "./rules/require-parameter-type.md"}
+{"gitdown": "include", "file": "./rules/require-readonly-react-props.md"}
 {"gitdown": "include", "file": "./rules/require-return-type.md"}
 {"gitdown": "include", "file": "./rules/require-types-at-top.md"}
 {"gitdown": "include", "file": "./rules/require-valid-file-annotation.md"}

.README/rules/require-inexact-type.md

@@ -0,0 +1,32 @@
+### `require-inexact-type`
+
+This rule enforces explicit inexact object types.
+
+#### Options
+
+The rule has one string option:
+
+- `"always"` (default): Report all object type definitions that aren't explicit inexact, but ignore exact objects.
+- `"never"`: Report all object type definitions that are explicit inexact.
+
+```js
+{
+  "rules": {
+    "flowtype/require-inexact-type": [
+      2,
+      "always"
+    ]
+  }
+}
+
+{
+  "rules": {
+    "flowtype/require-inexact-type": [
+      2,
+      "never"
+    ]
+  }
+}
+```
+
+<!-- assertions requireInexactType -->

.README/rules/require-readonly-react-props.md

@@ -2,7 +2,7 @@
 
 This rule validates that React props are marked as $ReadOnly. React props are immutable and modifying them could lead to unexpected results. Marking prop shapes as $ReadOnly avoids these issues.
 
-The rule tries its best to work with both class and functional components. For class components, it does a fuzzy check for one of "Component", "PureComponent", "React.Component" and "React.PureComponent". It doesn't actually infer that those identifiers resolve to a proper `React.Component` object. 
+The rule tries its best to work with both class and functional components. For class components, it does a fuzzy check for one of "Component", "PureComponent", "React.Component" and "React.PureComponent". It doesn't actually infer that those identifiers resolve to a proper `React.Component` object.
 
 For example, this will NOT be checked:
 
@@ -79,4 +79,4 @@ class Bar extends React.Component<Props> { }
 ```
 
 
-<!-- assertions requireReadOnlyReactProps -->
+<!-- assertions requireReadonlyReactProps -->