Add NSRDB PSM4 polar and polar TMY iotools (#2807)

* Add NSRDB PSM4 polar and polar TMY iotools

* Fix linter

* Set utc=True

* Add whatsnew, update tests

* Fix tests

* Set map_variables=False in tests

* Add get_nsrdb_psm4_polar_tmy

* Fix linter

* Add tests for erroneous inputs

* Fix linter

* Minor doc updates based on review

* Change economic zone to plural

Finalize v0.15.2 (#2784)

* set release date to June 16

* add missing contributors

* clean up formatting

* restore whatsnew entry mistakenly deleted in #2762

* rst formatting fix

* Apply suggestions from code review

Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>

* cleanup and imperative

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Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>

Finalize v0.15.1 (#2737)

* miscellaneous RST fixes

* add missing contributors

* whatsnew tweak

* fix typo

* Apply suggestions from code review

Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>

* fixes and suggestions

* fix typo

* one more fix

* fix spelling inconsistency in previous whatsnew file

* release date += 1

* Update docs/sphinx/source/whatsnew/v0.15.1.rst

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Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>

Update test_meteonorm expected values for new year (#2676)

Finalize v0.14.0 (#2656)

* rename v0.13.2 to v0.14.0

* rename 0.13.3 to 0.14.1

* set minimum solarfactors to 1.6.1

* add missing contributors

* fix minor rst warning

* release date += 1

* Update docs/sphinx/source/whatsnew/v0.14.0.rst

Finalize v0.13.1 (#2554)

* fix up whatsnew formatting

* add missing contributors for 0.13.1

* correct a few sphinx issues

* Update docs/sphinx/source/whatsnew/v0.13.1.rst

Co-authored-by: Adam R. Jensen <39184289+AdamRJensen@users.noreply.github.com>

* updates from review

Co-Authored-By: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>

* remove :term: from missing items

Co-Authored-By: RDaxini <143435106+RDaxini@users.noreply.github.com>

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Co-authored-by: Adam R. Jensen <39184289+AdamRJensen@users.noreply.github.com>
Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>
Co-authored-by: RDaxini <143435106+RDaxini@users.noreply.github.com>

Finalize v0.13.1 (#2554)

* fix up whatsnew formatting

* add missing contributors for 0.13.1

* correct a few sphinx issues

* Update docs/sphinx/source/whatsnew/v0.13.1.rst

Co-authored-by: Adam R. Jensen <39184289+AdamRJensen@users.noreply.github.com>

* updates from review

Co-Authored-By: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>

* remove :term: from missing items

Co-Authored-By: RDaxini <143435106+RDaxini@users.noreply.github.com>

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Co-authored-by: Adam R. Jensen <39184289+AdamRJensen@users.noreply.github.com>
Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>
Co-authored-by: RDaxini <143435106+RDaxini@users.noreply.github.com>

Finalize v0.13.0 (#2476)

* rename to 0.13.0, general cleanup

* add missing contributors

* a couple more 0.12.1->0.13.0 renames

* Change release date

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Co-authored-by: Adam R. Jensen <39184289+AdamRJensen@users.noreply.github.com>

Change freq M to MS (#2473)

* Change freq M to MS

* Use MS for test_clearsky

* Change to start.date().replace(day=1)

* Fix linter

Clarify which SAPM parameters are required by `module` in `pvsystem.s…

…apm` (#2435)

* Update pvsystem.py

* Update v0.12.1.rst

* Update pvsystem.py

* Update pvsystem.py

* list non-required param instead, units, formatting

* Update pvlib/pvsystem.py

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

* update param list (excl. param removed by #2433)

* add blank line for bullet list rendering

* separate C param

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Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>