Improve Post-Processing with GitHub API Integration

[kouloumos]

Part of the (optional) post-processing for transcription involves pushing output files to two GitHub repositories: bitcointranscripts and bitcointranscripts-metadata. Currently, this process requires cloning the repositories and setting their paths in a .env variable. We then change directories and execute git commands to create a new remote branch with the output files. The user/operator must then manually open a PR with the new branch.

As we move towards a hosted version of the transcription server, this process has limitations and disadvantages. To streamline the process and eliminate the need to clone repositories into the virtual server, we can use the GitHub API.

With the GitHub API, we only need an authorization token from a GitHub account. Using this token, we can create branches and commits off the main/master branch remotely, making the process more efficient and scalable.