doc: fix console.assert docs, message is a format

Documentation for console.assert incorrectly described message as a
single message, but it is a format.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
doc: added X.json to the LOAD_AS_FILE sudo code

Signed-off-by: Fedor Indutny <fedor@indutny.com>
Merge remote-tracking branch 'upstream/v0.10' into v0.10