CXX-3150 Post-release changes for 4.0.0

[eramongodb]

Followup changes after the 4.0.0 release.

• The static analysis report is renamed to static_analysis_report-X.Y.Z for consistency with prior reports.
• The "Driver status by family and version" section is renamed to "Driver Development Status" and its contents simplified to list only what is necessary.
  • The note regarding the meaning of "stability" is removed in favor of a more straightforward "Development Stability" column and a "Do not use in production!" notice for the master branch.
  • A new "ABI Stability" column is included in preparation of upcoming ABI v1 interfaces.
• The list of documentation versions in the API homepage is reformatted to better utilize screenspace.
• Hugo apparently appends a trailing / in the substitution of baseUrl, defeating the "fixes" in CXX-3097 add patch-apidocs-current-redirects.py #1238. (Something changed during Hugo version 0.92.2 -> 0.123.7?) The trailing / added in Fix broken links #1071 is restored (since it better matches the actual expansion) and appropriate changes made in usage sites.
• CXX-3097 update sitemaps and patch mongocxx-3.11.0 pages with redirects #1239 overlooked the required addition of an --exclude flag to the Hugo rsync --delete command to avoid the sitemap index file from being deleted. The flag is added, as well as a flag to exclude of the new mongocxx-v4 symlink in the Doxygen rsync command.
• The README contents are reorganized and updated with the new version table format and the latest conversion of releases/stable from a branch to a tag.

[kevinAlbs]

LGTM with minor fixes. I like the simplified compatibility table and version listing.