Unified approach to having email IDs of current authors in all guides

Look through all the guides in the Red Hat DevTools and Red Hat Developer Toolset doc sets to ensure that the names of the current writers are mentioned in the docs.xml file along with their emails IDs. Remove email IDs of the writers who aren't working on these anymore (let the names be there as they are)

https://access.redhat.com/documentation/en-us/red_hat_developer_toolset/8/
https://access.redhat.com/documentation/en-us/red_hat_developer_tools/1/

[UPD] Only Eclipse and DTS left.
Three compilers (LLVM, Rust, Go) - done.
An example to follow: https://access.redhat.com/documentation/en-us/red_hat_developer_tools/1/html/using_rust_1.39_toolset/