fix doc typos to cycle bots

Every edge will have its own `guard_variable` (uint32_t).

The compler will also insert calls to a module constructor:

The compiler will also insert calls to a module constructor:

.. code-block:: c++

    sancov -symbolize my_program.123.sancov my_program > my_program.123.symcov

The ``.symcov`` file can be browsed overlayed over the source code by

The ``.symcov`` file can be browsed overlaid over the source code by

running ``tools/sancov/coverage-report-server.py`` script that will start

an HTTP server.