Docs: Additional updates to build environment instructions
1. Add configuration instructions for ccache on Mac OS.
2. Move ccache instructions to new section, since setup applies to build environments on both Linux and Mac OS.
3. Make Mac OS references consistent.
4. Format branch tags, system paths and commands with <code> tag.

Change-Id: If5ae69c4de09542d5539882a10d84892d9e7d816
Signed-off-by: Collin El-Hossari <ceh@google.com>
4 files changed