More clean up of the scripts
In #18949, scripts have been improved, to respect PEP-8, to be executable, and a description on what they do has been added to the header. But some tasks are still pending:
* Replace old string formatting with `%` by new with `.format()`
* Review which scripts are still in use or can be useful
* Review which of the ones to keep work as expected (there are connections to GitHub API that could change, some were implemented for Python 2, and probably haven't been reviewed much since then)
* Add them to the documentation about contributing to pandas
* Unify the ones that make sense (the ones that look for issues with docstrings for example, or the ones that build the release)

Next are the available scripts.

**Scripts for the release manager**
* announce.py :  Script to generate contributor and pull request lists
* build_dist_for_release.sh : This builds the release cleanly & is building on the current checkout
* build_dist.sh : Build the distribution

**Script to check the docstrings**
* api_rst_coverage.py : Script to generate a report with the coverage of the API in the docs
* find_undoc_args.py : Script that compares the signature arguments with the ones in the docsting and returns the differences

**Other tools for developers**
* convert_deps.py : Convert the conda environment.yaml to a pip requirements.txt
* find_commits_touching_func.py : Search the git history for all commits touching a named method
* list_future_warnings.sh : Check all future warnings in Python files, and report them with the version where the FutureWarning was added (useful to find deprecated functions and methods that were supposed to be removed)
* merge-pr.py : Utility for creating well-formed pull request merges and pushing them to Apache?



