feat(doc): fill README

README.rst → README.md

-Summary
--------
-support for Sentry (getsentry.com)
+# CubicWeb-Sentry
+
+## Summary
+
+This cube add support of [Sentry](https://sentry.io/) for [CubicWeb](https://www.cubicweb.org/). It is a plug-in for the framework.
+
+## Install it
+
+1. `pip3 install cubicweb-sentry`
+2. `add_cube("sentry")`.
+
+## Configure it
+
+See `~/etc/cubicweb.d/<instance-name>/all-in-one.conf`

setup.py

@@ -46,7 +46,7 @@
 author_email = __pkginfo__["author_email"]
 classifiers = __pkginfo__["classifiers"]
 
-with open(join(here, "README.rst")) as f:
+with open(join(here, "README.md")) as f:
     long_description = f.read()
 
 # get optional metadatas