docs: add note about manual releasing for v3 artifacts

RELEASING.md

@@ -2,8 +2,8 @@
 
 ## Publishing via Travis (recommended)
 
-* Update the version number in each `package.json` file to latest version
-* Commit
+- Update the version number in each `package.json` file to latest version
+- Commit
 
         $ npm run release
         $ # review workspace and commits - if all looks good...
@@ -44,3 +44,41 @@ Echo the ~/.npmrc file and grab the token out of it.
 
     $ gem install travis
     $ travis encrypt NPM_KEY=${NPM_KEY} --add env.global
+
+## v3.0.0
+
+The native binaries required for post-install are trigerred [Github Actions](https://github.com/pact-foundation/pact-js/actions) on successful travis builds.
+
+Occasionally, you may need to generate these binaries manually. You can do so by running the command as follows (be careful to substitute branches/tagse etc.):
+
+To produce a darwin build, run from a Mac:
+
+```
+export NODE_PRE_GYP_GITHUB_TOKEN=<your github access token>
+npm install node-pre-gyp node-pre-gyp-github
+npm run build:v3
+rm -rf native/target
+npm run upload-binary
+```
+
+For linux64 (update version of node you need to release from in the docker image name). Please run the steps by hand:
+
+```
+docker run --rm -it -v $(pwd):/app node:latest bash
+apt-get update -y
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
+    sh -s -- -y
+#
+# choose 1 to progress
+#
+source $HOME/.cargo/env
+export NODE_PRE_GYP_GITHUB_TOKEN=<your github access token>
+cd /app
+rm -rf node_modules build
+npm ci
+npm install node-pre-gyp node-pre-gyp-github
+npm run build:v3
+rm -rf native/target
+npm run upload-binary
+```