DOC: Fix formula import convention.
DOC: Fix broken link
Merge pull request #1514 from jseabold/fix-formula-import

DOC: Fix formula import convention.
Merge pull request #1515 from jseabold/fix-docs-link

DOC: Fix broken link
DOC: Be clear about data attribute of Datasets
Merge pull request #1517 from jseabold/datasets-docs

DOC: Be clear about data attribute of Datasets
DOC: Update examples contributing docs for current practice.
Merge pull request #1516 from jseabold/uploading-examples

DOC: Update examples contributing docs for current practice.
DOC: Ask for release notes and example.
Merge pull request #1518 from jseabold/contributing-docs

DOC: Ask for release notes and example.
CLN: Improve warnings to avoid generic warnings messages

All generic Warnings have been replaced with specific warnings, which have
been consolidated into sm_exceptions.py.