fix some broken links

Signed-off-by: Francis Tisserant <tissf@free.fr>
Docs: expand a bit on the description to clear up confusion

Signed-off-by: John Thornton <jthornton@gnipsel.com>
French doc. update to follow John

Docs: expand a bit on the description to clear up confusion

Signed-off-by: Francis Tisserant <tissf@free.fr>
Merge remote-tracking branch 'origin/v2.5_branch'

Conflicts:
	docs/src/gcode/overview.txt