Riptable

Changes:
* Fix for Grouping.regroup() issue leading to bad results in merge2 with keep='first'
* Removed unused files
* Ignore .code-workspace files (part of VSCode)
* Add test with all nan tests
* Restore *args and **kwargs for GroupByOps.nth()

Changes:
* Docstring: Categorical.shift()
* Tests for groupby.shift() of flexible types fix
* Fix PyPI builds
* Disable warning about no-op GroupBy operation.
* Fixes and docstring updates for invoking groupbyops.nth()
* DocString:Link fixes
* Clearly format invalid dates, rather than raising exception.
* Fix str support from GB_MODE to GB_MEDIAN
* Docstring: Removed workaround info
* Add support for autocomplete placeholders
* Re-enable no-op warning
* Add ruff configuration to pyproject.toml
* Add black, flake8 and pydocstyle requirements sections to dev_tools/gen_requirements.py
* Pin to riptide_cpp-1.12.0
* Add missing flake8 request

Changes:
* Have Cat.as_string_array convert string list to dtype=S

Changes:
* Count uniques fix speedup
* Set remove_blanks in accum_ratiop to False by default
* Optimizing numba_apply
* Docstring: Categorical.count()
* Tutorial: filters edits
* Docstrings + bug fix: Cat.as_string_array(), Cat.expand_array()
* Tutorial: categorical updates
* Improve Dataset.as_recordarray() handling of datetimes
* Docstring: FastArray.set_name space error
* Tutorial: spelling
* Test for CMultiKeyPrepare fix.
* Pin to riptide_cpp-1.11.4

Changes:
* Docstrings: Struct.shape, Struct.col_filter
* rt_datetime strftime methods (minor reorg + docstrings)
* Error on transform for cumsum
* Delete unused directory
* Docstrings: Struct display properties
* DateTimeNano._random() start and end bug fix + test
* Docstring: Date.range()
* Docstrings: DateTimeNano.random(), DateTimeNano.random_invalid()
* Docstrings: rt.where(), fa.where()
* Avoid invoking rc.Reduce() for non-1D arrays.
* Re-create env rather than install.

* Change sys.path to ../../
* Intro converted to reStructuredText
* Make GroupByOps an abstract base class
* Add pymoo for benchmarks
* Doc: Exclude benchmarks folder from Sphinx autoapi build
* Doc: rt.full
* Docstrings: Add note to Date.min(), DateSpan.min() about NaNs
* Docstrings: dtn.min, dtn.max
* Doc: Change Sphinx default role to x-ref Python objs
* Docstring: rt.empty, rt.empty_like
* Docstrings: rt.repeat, rt.tile
* Doc: Turn off typehints in html
* Docstrings: Struct.is_valid_colname, Struct.get_restricted_names, Struct.col_rename
* Docstring: rt.arange
* Update GitHub actions to Node16