docs(indent-binary-ops): improve docs, close typescript-eslint#226

Author: antfu

packages/eslint-plugin-plus/rules/indent-binary-ops/README.md

@@ -1,7 +1,7 @@
 ## Rule Details
 
 Indentation for binary operators in multiline expressions.
-This is a supplement to the [`indent`](https://eslint.style/rules/default/indent) rule.
+This is a supplement to the [`indent`](https://eslint.style/rules/default/indent) rule. They are supposed to be used together with the same indentation size.
 
 ## Options
 
@@ -11,18 +11,28 @@ For example, for 2-space indentation:
 
 ```json
 {
-  "indent-binary-ops": ["error", 2]
+  "@stylistic/indent": ["error", 2],
+  "@stylistic/indent-binary-ops": ["error", 2]
 }
 ```
 
 Or for tabbed indentation:
 
 ```json
 {
-  "indent-binary-ops": ["error", "tab"]
+  "@stylistic/indent": ["error", "tab"],
+  "@stylistic/indent-binary-ops": ["error", "tab"]
 }
 ```
 
+This rule works by:
+
+- Only check for binary operations that are multiline.
+- Align the indentation of the second line with the same indentation of the first line (handled by the `indent` rule)
+- In some conditions (e.g. last line ends with an open bracket), the indentation of the second line will be one level increased to the first line's indentation.
+
+## Examples
+
 Examples of **incorrect** code for this rule:
 
 :::incorrect