Update description

CONTRIBUTING.md

@@ -2,12 +2,10 @@
 
 ## Upgrading DuckDB
 
-`go-duckdb` includes a copy of the DuckDB amalgamation (`duckdb.cpp`, `duckdb.h` and `duckdb.hpp`) and pre-compiled static libraries for faster builds on common platforms (see the `deps` directory). It uses Github Actions to pre-compile the static libraries based on the amalgamation code. This approach is inspired by a combination of [go-sqlite3](https://github.com/mattn/go-sqlite3) and [v8go](https://github.com/rogchap/v8go).
-
 To upgrade to a new version of DuckDB:
 
-1. Change `DUCKDB_VERSION` in `Makefile`
-2. Run `make deps.source`
-3. Push the updated amalgamation files in a new PR
-4. Wait for Github Actions to pre-compile the static libraries in `deps` and push them to the PR
-5. Once the static libraries have been pushed, you can merge the PR to master
+1. Create a new branch with the current version number in it. E.g. `v0.9.0`.
+2. Change `DUCKDB_VERSION` in `Makefile` to match the version in the branch name.
+3. Push the updated `Makefile` and create a PR.
+4. Wait for Github Actions to pre-compile the static libraries in `deps`. They will be committed automatically to the branch.
+5. If everything looks good, the PR will be merged.