Fixes to bundle a README.txt file.
Fixes to bundle a README.txt file.

This is needed for a Python package distribution.

kevincon/gcovr,thatguystone/gcovr,thatguystone/gcovr,kevincon/gcovr,cloudsmith-io/gcovr,cloudsmith-io/gcovr,cloudsmith-io/gcovr,kevincon/gcovr,kevincon/gcovr,thatguystone/gcovr,thatguystone/gcovr,cloudsmith-io/gcovr