Add a simple 'developers' page and a link from the README (#7)

* Add a simple 'developers' page and a link from the README

* Fix markdown relative link syntax

* Developers page: move user-space install instruction into the build phase

README.md

@@ -44,4 +44,6 @@ The Flask default port 5000 can be changed with the `--ports` option.
 
 **:warning: net viel is meant for *local* use only. Do *not* expose this to the Internet as-is. Bad things will happen! :warning:**
 
+## Development
 
+To run net viel locally and make changes to the code, follow intructions on [this page](docs/developers.md).

docs/developers.md

@@ -0,0 +1,46 @@
+# Development
+
+## Dependencies
+
+You need the Python bindings for `notmuch`. In Debian/Ubuntu, this is provided by the `python3-notmuch` package.
+
+## Fork the two repositories
+
+Fork the `netviel` backend and frontend:
+
+* https://github.com/DavidMStraub/netviel
+* https://github.com/DavidMStraub/netviel-frontend
+
+And clone them to your computer.
+
+## Prepare the backend
+
+Build it like so:
+
+`cd netviel && python3 -m pip install -e . --user`
+
+## Prepare the frontend
+
+Install NVM:
+
+`wget -qO- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash`
+
+(you can replace `bash` with your shell of choice.)
+
+Then use NVM to install the latest NPM, and use it in the frontend directory you have cloned:
+
+`nvm install --latest-npm`
+
+`cd netviel-frontend && npm install`
+
+## Run a test server
+
+Run the backend first:
+
+`cd netviel && export FLASK_DEBUG=1 && python3 -m netviel`
+
+(this avoids the need for admin rights). In a separate terminal, run the frontend:
+
+`cd netviel-frontend && npm run start`
+
+This will open a browser and fetch data from the local backend. Note that both run on `localhost` but the backend runs on port 5000 and the frontend on 8001.