added README for pylint plugin (#7277)

plugins/pylint/README.md

+# pylint 
+
+This plugin adds code analysis for python through [Pylint](https://www.pylint.org/).
+
+To use it, add `pylint` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... pylint)
+```
+
+## Aliases
+
+| Alias        | Command              | Description                                                                                                              |
+| -------------| -------------------- | -------------------------------------------------------------------------------------------------------------------------|
+| pylint-quick | `pylint --reports=n` | Displays a set of reports each one focusing on a particular aspect of the project, default set `no` for multiple reports |                                         |