feat: Fix contribution docs

.env.example

@@ -9,3 +9,6 @@ GATSBY_ALGOLIA_INDEX_PREFIX=test-sentry-
 # ALGOLIA_ADMIN_KEY=
 # ALGOLIA_INDEX=0
 # SENTRY_AUTH_TOKEN=
+DATABASE_URL=postgresql://postgres:postgres@localhost:5432/changelog
+NEXTAUTH_URL=http://localhost:3000
+NEXTAUTH_SECRET=secret

CONTRIBUTING.md

@@ -0,0 +1,35 @@
+<p align="center">
+  <a href="https://sentry.io/?utm_source=github&utm_medium=logo" target="_blank">
+    <img src="https://sentry-brand.storage.googleapis.com/sentry-wordmark-dark-280x84.png" alt="Sentry" width="280" height="84">
+  </a>
+</p>
+
+## Setting up an Environment
+
+We use Next.js, `yarn` and `volta` to manage the environment.
+
+```
+cp .env.example .env.development
+yarn
+yarn dev
+```
+
+With that, the repo is fully set up and you are ready to open local docs under http://localhost:3000
+
+### Database
+
+There is a compose file to start a local postgres db:
+
+```
+docker-compose up -d
+```
+
+If you already run a local postgres, it will create a `changelog` table.
+
+The inital setup or the clean the database call:
+
+```
+yarn prisma migrate reset
+```
+
+To add new entries, visit `/changelog/_admin` you need to have a Google Account in the Sentry org to login.