…le to detec header

(cherry picked from commit 6bc72a4)

Update documentation for FAVE 2:
 * Include warning for old users on reading migration guide.
 * Write migration guide with FAQ
 * Simplify TOC code
 * Add index.rst for code and usage sections of docs
 * Add sphinx-project module into conf to make doc updates easier

This commit adds some testing for the cmudictionary.py module.

In testing cmudictionary.CMU_Dictionary.add_dictionary_entries()
a bug was uncovered in .check_transcription() which caused the
output file to have more spaces than necessary. The cause was that
function did not split the phone string when it was supposed to.
This commit fixes the error and includes the test to prevent regression.

An error in cmudictionary.py caused add_dict to be overwritten and
change type when a transcribed word was not in the cmu dictionary and
had not yet been added to the output dictionary. This led to an obvious
type error and a not obvious failure to add custom dictionaries. This
commit fixes the issue by adding the given word as a key to add_dict
and adds a test to prevent regressions.

Resolves JoFrhwld#59

Resolves JoFrhwld#65 by checking the data type of the first time field. If it's not a float, we assume it's a header row and remove it from the returned list. Otherwise the function returns as previously.

Squashed commit of DerMoehre's PR JoFrhwld#73

Co-authored-by: JoFrhwld <JoFrhwld@gmail.com>
Co-authored-by: Christian Brickhouse <chrisbrickhouse@users.noreply.github.com>

This reverts commit 5983ed6.

* Update workflows to install package dependencies like numpy for use in tests
* Cache installed dependencies so that future runs are faster
* Upgrade setup-python to v4 from v3

…d#83)" (JoFrhwld#90)

This reverts commit 25d7563.

Add flake8 and pytest as dev deps.

* Workflows upgraded to setup-python v4.
* Workflows now install deps using poetry.
* Lint and test run through poetry interface.
* Deps cached for faster testing in later runs.