bug#35337: Document the recommended way to get the :0s out of -c output

Boy they really blew it when they invented -c, (info "(grep) General Output Control") ‘-c’ ‘--count’ Suppress normal output; instead print a count of matching lines for each input file. With the ‘-v’ (‘--invert-match’) option, count non-matching lines. (‘-c’ is specif

bug#35339: Say what buffering is not --line-buffered

On (info "(grep) Other Options") ‘--line-buffered’ Use line buffering on output. This can cause a performance penalty. OK, but say what will happen if one doesn't use this. Paragraph buffering? Page buffering?