add documentation about making release

Author: maxulysse

.github/RELEASE_CHECKLIST.md

@@ -1,6 +1,6 @@
 # Release checklist
 
-This checklist is for our own reference
+> This checklist is for our own reference, to help us prepare a new release
 
 1.  Check that everything is ready to go
 

docs/RELEASE.md

@@ -0,0 +1,38 @@
+# RELEASE
+
+> This document is for helping Sarek core developers and anyone joining the team to prepare a new release
+
+## [CHECKLIST](https://github.com/SciLifeLab/Sarek/blob/master/.github/RELEASE_CHECKLIST.md)
+
+This checklist is for our own reference, to help us prepare a new release.
+Just follow it and be sure to check every item on the list.
+
+## [Helper script](https://github.com/SciLifeLab/Sarek/blob/master/scripts/do_release.sh)
+
+This script will update the version number in the following files:
+
+-   [CHANGELOG.md](https://github.com/SciLifeLab/Sarek/blob/master/CHANGELOG.md)
+    -   Will change Unreleased to correct version number and add codename and date
+-   [Dockerfile](https://github.com/SciLifeLab/Sarek/blob/master/Dockerfile)
+    -   Will update to correct version number
+-   [Singularity](https://github.com/SciLifeLab/Sarek/blob/master/Singularity)
+    -   Will update to correct version number
+-   [conf/base.config](https://github.com/SciLifeLab/Sarek/blob/master/conf/base.config)
+    -   Will update to correct version number
+
+### Usage
+
+### Usage
+
+```bash
+./scripts/do_release.sh -r "<RELEASE>" -c "<CODENAME>"
+```
+
+-   `-r|--release` specify the new version number
+-   `-c|--codename` specify the codename
+
+### Example
+
+```bash
+./scripts/do_release.sh -r "2.2.0" -c "Skårki"
+```