Doc release update process

The ACRN release process starts when the code is frozen on the candidate release branch, such as release_2.4. Documentation changes continue on the master branch while developers are validating and testing the release candidate. Once the release candidate branch is declared ready, we need to propagate all the documentation changes that were done on the master branch back into this release candidate branch as well. In the past, doc changes were cherry-picked from the master branch to the release candidate branch, but for a while now we simplified this process (and reduced the chance of missing a documentation change) by essentially merging all the documentation changes made on the master branch since the release candidate branch was made. We do this by making a working directory with content from the master branch, checking out the release candidate branch, and then copying that working directory content onto the checked-out release candidate to create a single pull-request with all the changes. Here's the process:

rm -rf ~/acrn-master && mkdir ~/acrn-master
cd ~/projectacrn/acrn-hypervisor/doc
git checkout master
git fetch upstream
git merge upstream/master
git push origin master

make clean
cp -r . ~/acrn-master/doc
cd ../misc
mkdir ~/acrn-master/misc

# the --parents option maintains the directory structure in the destination directory
cp --parents *.rst ~/acrn-master/misc
cp --parents */*.rst ~/acrn-master/misc
cp --parents */*/*.rst ~/acrn-master/misc
cp --parents */*/*/*.rst ~/acrn-master/misc
# until the copy fails, then get the schema files that contain configuration option documentation
cp --parents config-tools/schema/*.xsd ~/acrn-master/misc

cd ..
git checkout upstream/release_2.4
git checkout -b update-docs-2.4
cp -r ~/acrn-master/* .

# you could do a "make html" here to verify CI doc build will work...

git add .
git status 
# verify all staged files are added (from the /doc and /misc directories)

git commit -s
# in the commit message add "Tracked-On: #5692" to allow the .xsd file changes to get through CI checks

git push origin update-docs-2.4

From here, head over to https://github.com/projectacrn/acrn-hypervisor and create a PR, changing the base to be the release_2.4 branch (not master). You should see just the changed documents listed as changed files, and there should be no merge conflicts. Wait for the CI system to pass.