Add Makefile section to README-dev.md

Author: dkropachev

README-dev.md

@@ -14,3 +14,17 @@ Once you have installed the above software, you can build and preview the docume
 ## Custom commands
 
 To generate the reference documentation of the driver, run the command `make javadoc`. This command generates the reference documentation using the Javadoc tool in the `_build/dirhtml/<VERSION>/api` directory.
+
+## Using the Makefile
+
+Most day-to-day tasks are wrapped in the top-level `Makefile` so you do not have to remember long Maven invocations. Common targets include:
+
+- `make download-all-dependencies` pre-fetches all Maven artifacts to warm local caches.
+- `make compile-all` compiles main and test sources without running tests, skipping format, clirr, and animal-sniffer checks for speed.
+- `make test-unit` runs the fast unit-test suite; use `MVNCMD` to tweak the underlying Maven command if needed.
+- `make test-integration-scylla` and `make test-integration-cassandra` execute CCM-backed integration suites. Export `SCYLLA_VERSION` or `CASSANDRA_VERSION` to pin specific server versions before invoking.
+- `make check` executes `mvn verify -DskipTests` for static analysis, while `make fix` applies code formatters via `mvn fmt:format`.
+- `make fix` executes `mvn fmt:format` to format the code.
+- `make clean` removes Maven targets, shaded artifacts, and release backups to reset the tree.
+
+The Makefile automatically installs the shaded Guava dependency and, for integration tests, bootstraps the appropriate CCM toolchain and raises kernel `aio-max-nr` when required. If a target fails because the toolchain is missing, rerun after installing the prerequisites highlighted in the target output.