Add repository maintenance documentation

documentation/repository-maintenance.md

@@ -0,0 +1,27 @@
+# Repository Maintenance
+
+## Diagrams
+- Diagrams were created with [draw.io](draw.io).
+- To update a diagram:
+  1. Go to [draw.io](draw.io).
+  1. Click on *File > Open from* and choose the location of the diagram you want to update.
+  1. Once open in draw.io, you may update it.
+  1. Export the diagram to this repository's directory and add commit it.
+  
+  
+## Generating the Changelog
+We use [github-changelog-generator](https://github.com/github-changelog-generator/github-changelog-generator) to 
+generate release Changelogs. To be consistent with previous Changelogs, the following flags should be passed to the 
+command:
+
+```
+--user vulcanize
+--project vulcanizedb
+--token {YOUR_GITHUB_TOKEN}
+--no-issues
+--usernames-as-github-logins
+--since-tag {PREVIOUS_RELEASE_TAG}
+```
+
+More information on why your github token is needed, and how to generate it here:https://github
+.com/github-changelog-generator/github-changelog-generator#github-token