* Reformat whitespace in README.md
* hifi_vckpg.py: Remove macos var/temp hack for vcpkg
* hifi_vckpg.py: Add ability to override HIFI_QT_INSTALL_ROOT dir with environment variable.
* hifi_vckpg.py: Update macos url for pre-built qt 5.12.3 on S3.
* cmake/ports/bullet3/portfile.cmake: add comment to force change in vcpkg hash.
* tools/qt-builder/README.md: updated formatting and added details about how to generate symbols for macos and pc
* tools/qt-builder: added prepare python scripts for symbols
* cmake/macros/SetupQt.cmake: Remove hardcoded var/temp qt cmake path
hifi_vcpkg.py will now download a new version of qt that contains release symbols.
made minor changes to bullet3/portfile.cmake to trigger a new vkpkg hash.
