Add development guide (#1722)

DEVELOPMENT.md

@@ -0,0 +1,25 @@
+# Ghostfolio Development Guide
+
+## Git
+
+### Rebase
+
+`git rebase -i --autosquash main`
+
+## Dependencies
+
+### Nx
+
+#### Upgrade
+
+1. Run `yarn nx migrate latest`
+1. Make sure `package.json` changes make sense and then run `yarn install`
+1. Run `yarn nx migrate --run-migrations`
+
+### Prisma
+
+#### Create schema migration (local)
+
+Run `yarn prisma migrate dev --name added_job_title`
+
+https://www.prisma.io/docs/concepts/components/prisma-migrate#getting-started-with-prisma-migrate