docs: add maintainance info (#271)

refs: #194

Author: aladdin-add

README.md

@@ -18,11 +18,11 @@ Additional ESLint rules for Node.js
 npm install --save-dev eslint eslint-plugin-n
 ```
 
-| Version | Supported Node.js | Supported ESLint Version |
-|---------|-------------------|---------------------------|
-| 17.x   | `^18.18.0 \|\| ^20.9.0 \|\| >=21.1.0`  | `>=8.23.0`          |
-| 16.x   | `>=16.0.0`   | `>=7.0.0`          |
-| 15.x   | `>=12.22.0`  | `>=7.0.0`          |
+| Version | Supported Node.js | Supported ESLint Version | Status |
+|---------|-------------------|---------------------------|--------|
+| 17.x   | `^18.18.0 \|\| ^20.9.0 \|\| >=21.1.0`  | `>=8.23.0`          | 🏃‍♂️actively maintained |
+| 16.x   | `>=16.0.0`   | `>=7.0.0`          | ⚠️EOL |
+| 15.x   | `>=12.22.0`  | `>=7.0.0`          | ⚠️EOL |
 
 **Note:** It recommends a use of [the "engines" field of package.json](https://docs.npmjs.com/files/package.json#engines). The "engines" field is used by `n/no-unsupported-features/*` rules.