Fix typo in README
use 'mouseup' instead of 'click'

click breaks  CTRL+click to open a tab on firefox and chrome
add a what is it comment in the index
Jobs cannot be run in parallel or they corrupt the compilation database
add the '-a' option to process all files from the compilation database
add a progress
Fix processing if the compile_commands.json  contains empty files
fix finding the context of the uses for the local symbols