Puncturedfem

Features
- [x] add `TracePlot` class
- [x] add `MeshPlot` class
- [x] add `GlobalFunctionPlot` class
- [x] add `LocalFunctionPlot` class
- [x] add `get_quad_dict()` function
- [x] make `edgespaces` an optional parameter in `LocalFunctionSpace` init method
Examples
- [x] `examples/ex1d-hat-tile.ipynb`: add example of hat tile local basis functions
Tests
- [x] deprecate `unittest` in favor of `pytest`
- [x] add `test_edge_space`
- [x] add `test_solver`
Maintenance
- [x] use enumerate to replace `range(len(...))` loops
- [x] rectify nested min/max statements
- [x] `locfun.locfunsp`: make interior value calculation optional
- [x] use `functools.partial` to pass logarithmic terms to integrators
- [x] `locfun.poly.poly`: use list of tuples for polynomial initialization
- [x] clean up integration methods
- [x] add safety check to `add_edge()` method in `PlanarMesh`
- [x] `mesh.edgelib.teardrop`: pass `alpha` as keyword argument
- [x] `solver.solver`:
- [x] move color printing to separate module
- [x] move plotting functions to separate module
- [x] add init file for `util` subpackage
- [x] rename classes to use CapWords convention
- [x] fix invalid names introduced by class renaming
- [x] fix type hints in tests
Bug fixes
- [x] fix colorbar position in contour plots

- [x] change exceptions to specific error types
- [x] document TODO comments in `doc/TODO.md`
- [x] modify `CHANGELOG.md`, `TODO.md`, `WISHLIST.md` to reflect semantic versioning
- future versions will use `git` branches to isolate development
- git tags and GitHub releases will be used to track versions
- small commits get a descriptive message
- branch merges get a release number

- rename `id` variables to either `idx` or `key` to avoid shadowing built-ins

- write docstrings
- modules
- classes
- methods
- functions
- add `__init__.py` to `solver` subpackage

- use generators where appropriate
- fix imports
- use f-strings
- fix spelling errors
- use `enumerate` in loops where appropriate
- fix superfluous `return` statements
- fix unnecessary `else` statements
- change underscore methods in `edgelib` to capitalized
- update `edge` class to reflect change
- update `ex0` example to reflect change
- add type hints
- functions
- methods
- classes
- fix other `pylint` and `mypy` errors
- update `pyproject.toml`

- rename `setup.cgf` to `.flake8` (until `flake8` supports `pyproject.toml`)
- update `devtools/convert_examples.sh` to support being executed from any directory