add safety measures for base doc repo

read comments at: https://github.com/software-mansion/scarb/pull/2942/changes#r2704418534

to consider: 
- git config might off the target or the commit might exists locally only 
- `--offline` option (if there is a call from local to remote to check if repos are in sync)
- verification if the link actually exists 
- repo privacy settings can corrupt the documentation 
- check if commit is stable

