docs: Update contributing doc with some detailed steps (#396)

Also updates the update-ecosystem-lists.py script to copy the
schema.json file over to the linter. (This avoids people having to run
go generate on the linter as an extra step)

Signed-off-by: Rex P <[email protected]>

Author: another-rex

CONTRIBUTING.md

@@ -21,3 +21,22 @@ All submissions, including submissions by project members, require review. We
 use GitHub pull requests for this purpose. Consult
 [GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
 information on using pull requests.
+
+## Adding a new ecosystem
+
+To add a new ecosystem, follow these steps:
+
+1.  **`ecosystems.json`**: Add an entry for the new ecosystem and it's description.
+    * If your ecosystem has multiple separate release, please include how releases are specified.
+
+2.  **Database-specific prefix**: Generally a new ecosystem will introduce a new database-specific ID prefix (e.g., `GHSA` for GitHub Security Advisories), please add it to:
+    *   The "Database-specific prefixes" table in `docs/schema.md`.
+    *   The `prefix` pattern within `validation/schema.json`.
+
+3.  **`README.md`**: Add the new ecosystem to the list of data exporters in the README.
+
+4.  **Run update script**: Finally, run `python3 ./scripts/update-ecosystems-lists.py`. This script will automatically update the following files based on your changes to `ecosystems.json`:
+    *   `bindings/go/osvschema/constants.go`
+    *   The main ecosystem table in `docs/schema.md`
+    *   The ecosystem enum in `validation/schema.json`
+    *   Make a copy of the `validation/schema.json` for the linter in `tools/osv-linter/internal/checks/schema_generated.json`

scripts/update-ecosystems-lists.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 import json
+import shutil
 
 MARKDOWN_TABLE_MARKER_START = '<!-- begin auto-generated ecosystems list -->'
 MARKDOWN_TABLE_MARKER_END = '<!-- end auto-generated ecosystems list -->'
@@ -141,5 +142,5 @@ def update_go_constants():
 
 update_go_constants()
 update_json_schema('validation/schema.json')
-update_json_schema('tools/osv-linter/internal/checks/schema_generated.json')
+shutil.copy('validation/schema.json', 'tools/osv-linter/internal/checks/schema_generated.json')
 update_schema_md()