Correct doc links to CI commands

Update doc for 6.1 release

Update checksum for latest patch release bundle in the doc

Update the doc for the latest patch release and NDK

Fix a typo and a link in the doc

Update doc and config files to 5.10

Update doc and config files to 5.9.2 SDK built with NDK 26b

Change section headers in README

Update incorrect SDK name and CI link in doc to 5.8

Update to Swift 5.7.1, save SDK on CI, and disable new NIO test that'…

…s failing