add act readme, fix makefile yarn call to work as per: actions/setup-…

…node#182 (comment)

.github/workflows/GITHUBACTIONS-README.md

@@ -0,0 +1,42 @@
+GitHub Actions Notes
+====================
+
+Local Builds
+---------------
+You can locally test the GitHub Actions defined in this directory using [nektos act](https://github.com/nektos/act).
+
+This allows you to run an equivalent CI build on your local machine. For example:
+```console
+    $ act
+```
+Note: The first time you run [act](https://github.com/nektos/act), it can take a long time (with no output) to download
+the various docker goodies. Give it time before deciding it is stuck.
+
+To get a list of available jobs, run:
+```console
+    $ act -l
+```
+To run a specific job, use the `-j` flag:
+```console
+    $ act -j <job-name>
+```
+For example, to run the `build` job from the `ci.yml` file, use this command:
+```console
+    $ act --workflows .github/workflows/ci.yml -j build
+```
+If running on Apple silicon, and you see docker errors, try launching act with this flag:
+```console
+   act --container-architecture linux/amd64
+```
+Without this flag, I saw this warning:
+```console
+WARN  ⚠ You are using Apple M-series chip and you have not specified container architecture, you might encounter issues while running act. If so, try running it with '--container-architecture linux/amd64'. ⚠
+```
+and this error:
+```console
+...   🐳  docker exec cmd=[bash --noprofile --norc -e -o pipefail /var/run/act/workflow/1] user= workdir=
+| docker compose build
+[+] Building 0.0s (0/0)                                                         
+| permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/_ping": dial unix /var/run/docker.sock: connect: permission denied
+...
+```

Makefile

@@ -33,8 +33,8 @@ docker:
 build: yarn go-build
 
 yarn:
-	yarn && NODE_OPTIONS=--openssl-legacy-provider yarn build
-# && yarn version --new-version $(VERSION)
+	corepack yarn && NODE_OPTIONS=--openssl-legacy-provider corepack yarn build
+# && corepack yarn version --new-version $(VERSION)
 
 go-build:
 	echo "VERSION: $(VERSION)"