Added developer info to top-level README

README.md

@@ -19,3 +19,13 @@ The basic command above will install the latest available version of the selecte
 ## Licensing
 
 The charts in this repository are licensed under the Apache Licence version 2.0, however the software that they install may be under one or more different and more restrictive licences.  For example the `gate-teamware` chart installs [GATE Teamware](https://github.com/GateNLP/gate-teamware), which is released under the AGPL, and [PostgreSQL](https://www.postgresql.org), which is released under its own BSD-like licence.  It is your responsibility to ensure that your use of any of these charts complies with all applicable licences.
+
+## Information for chart developers
+
+All updates to charts in this repository must be done via pull requests.  To modify a chart make a new branch off the current `main`, push your changes to that branch, and start a pull request.  The following automatic checks are performed on each pull request, and must all pass before the PR is merged:
+
+- if the PR makes _any_ changes within a given chart directory, then the PR _must_ update the `version` number of that chart in the relevant `Chart.yaml`.  PRs that change a chart but do not bump its version number will be rejected.
+- if the chart declares any `dependencies` in its `Chart.yaml` then the corresponding `Chart.lock` _must_ exist - you can create this using `helm dependency update`
+- all dependencies in the `Chart.lock` _must_ resolve - if a dependency has been removed from its remote repository you will have to edit `Chart.yaml` if necessary and run `helm dependency update` to re-generate the lock file
+
+When the PR is merged to `main` all modified charts will be automatically deployed to `https://repo.gate.ac.uk/repository/charts`