* Fix mis-spelling of `ticks_add` in code examples.
* Be consistent about parentheses after function names.
* Be consistent about formatting of function, variable and constant names.
* Be consistent about spaces and punctuation.
* Fix some language errors (missing or wrong words, wrong word order).
* Keep line length under 90 chars.
Signed-off-by: Christopher Arndt <chris@chrisarndt.de>
It's mandatory function which should be present in every port. Even if
it's not, in the stdlib intro we waarn users that a particular port can
lack anything of described in the docs.
