Add comments to release script

.github/release.sh

@@ -5,6 +5,7 @@ BRANCH_NAME="release/$1"
 PR_TITLE="Release $1"
 PR_BODY="Update Diffblue Cover to $1"
 
+# If a second parameter is provided then we create an "testing" PR instead of a "release" PR
 if [ -n "$2" ]; then
      echo "Testing internal build"
      BRANCH_NAME="testing/$1"
@@ -14,13 +15,15 @@ fi
 git checkout -b "$BRANCH_NAME"
 
 if [ -n "$2" ]; then
+     # If testing an internal build the version of the docker image will be the branch name followed by the version (all lower case with "/"s replaced by "-"s)
      DOCKER_VERSION=$(echo "${2,,}-${1,,}" | sed 's/\//-/g')
      sed -i "s/cli:[0-9]\{4\}\.[0-9]\{2\}\.[0-9]\{2\}-jdk/cli:$DOCKER_VERSION-jdk/g" Dockerfile
      sed -i "s|diffblue\/cover-cli:|docker.io/diffblue\/internal-cover-cli:|g" Dockerfile
 else
      sed -i "s/cli:[0-9]\{4\}\.[0-9]\{2\}\.[0-9]\{2\}-jdk/cli:$1-jdk/g" Dockerfile
 fi
 
+# Push changes made to root Dockerfile to all children
 ./build.sh
 git add Dockerfile
 git add */Dockerfile