Added README.md

README.md

+This repository just contains an [original Sentry setup instructions](https://hub.docker.com/_/sentry/) but with using of Docker Compose
+
+# Sentry
+
+Sentry is a realtime, platform-agnostic error logging and aggregation platform
+
+## What is Sentry?
+
+Sentry is a realtime event logging and aggregation platform. It specializes in monitoring errors and extracting all the information needed to do a proper post-mortem without any of the hassle of the standard user feedback loop.
+
+## How to setup a full Sentry instance
+
+1. Specify your DB and SMTP server credentials in `.env` file
+
+2. Generate a new secret key to be shared by all `sentry` containers. This value will then be used as the SENTRY_SECRET_KEY environment variable.
+    ``` bash
+    docker-compose run --rm sentry config generate-secret-key
+    ```
+
+3. Insert generated secret key into `.env` file
+
+4. If this is a new database, you'll need to run `upgrade`
+    ``` bash
+    docker-compose run --rm sentry upgrade
+    ```
+
+5. Now start up Sentry server
+    ``` bash
+    docker-compose up -d sentry
+    ```
+
+6. The default config needs a celery beat and celery workers, start as many workers as you need (each with a unique name)
+    ``` bash
+    docker-compose up -d cron
+    docker-compose up -d worker
+    ```