Besides other documentation changes, this commit ensures the generated
HTML doc for HexDocs.pm will become the main source doc for this Elixir
library which leverage on latest ExDoc features.
Coverage remained the same at 99.02% when pulling b1d7ee74e30d2af796bd6777ef9466a6c4bb4279 on kianmeng:misc-doc-changes into e5afe54efe664b1cd0617fcaedae8d9e9e5d977a on elixir-geolix:master.
Besides other documentation changes, this commit ensures the generated HTML doc for HexDocs.pm will become the main source doc for this Elixir library which leverage on latest ExDoc features.