docs: update docs directory in working-with-rules (#15830)

Author: mdjermanovic

docs/src/developer-guide/working-with-rules.md

@@ -11,7 +11,7 @@ Each rule in ESLint has three files named with its identifier (for example, `no-
 
 * in the `lib/rules` directory: a source file (for example, `no-extra-semi.js`)
 * in the `tests/lib/rules` directory: a test file (for example, `no-extra-semi.js`)
-* in the `docs/rules` directory: a Markdown documentation file (for example, `no-extra-semi`)
+* in the `docs/src/rules` directory: a Markdown documentation file (for example, `no-extra-semi.md`)
 
 **Important:** If you submit a **core** rule to the ESLint repository, you **must** follow some conventions explained below.