Fix: Missing command in the installation section of sphinx-doc

[kd610]

This PR fix is to address the issue #1841. @DavidKorczynski has updated the installation section of Sphinx documentation. However, the shell does not remain in the work directory after executing the script build_all.sh. Hence, I have added the command cd work to ensure the subsequent processes can be executed correctly. This approach maintains consistency with the command style in Option 2.

[DavidKorczynski]

Thanks! Could you sign off the commit?
This should do the job:
"

To add your Signed-off-by line to every commit in this branch:

Ensure you have a local copy of your branch by [checking out the pull request locally via command line](https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/checking-out-pull-requests-locally).
In your local branch, run: git rebase HEAD~1 --signoff
Force push your changes to overwrite the branch: git push --force-with-lease origin fix-installation-doc

"

[kd610]

Thank you for your response! I just signed my commit by executing the commands above. I appreciate you sharing them with me!