Add poetry badge to project

Author: pappasam

README.md

@@ -5,6 +5,7 @@
 [![image-python-versions](https://img.shields.io/badge/python->=3.8-blue)](https://python.org/pypi/jedi-language-server)
 [![image-pypi-downloads](https://static.pepy.tech/badge/jedi-language-server)](https://pepy.tech/projects/jedi-language-server)
 [![github-action-testing](https://github.com/pappasam/jedi-language-server/actions/workflows/testing.yaml/badge.svg)](https://github.com/pappasam/jedi-language-server/actions/workflows/testing.yaml)
+[![poetry](https://img.shields.io/endpoint?url=https://python-poetry.org/badge/v0.json)](https://python-poetry.org/)
 
 A [Language Server](https://microsoft.github.io/language-server-protocol/) for the latest version(s) of [Jedi](https://jedi.readthedocs.io/en/latest/). If using Neovim/Vim, we recommend using with [coc-jedi](https://github.com/pappasam/coc-jedi). Supports Python versions 3.8 and newer.