Track cfg and MANIFEST.in files

Author: bobleesj

Diff for: .isort.cfg

@@ -0,0 +1,4 @@
+[settings]
+line_length = 115
+multi_line_output = 3
+include_trailing_comma = True

Diff for: MANIFEST.in

@@ -0,0 +1,14 @@
+include AUTHORS.rst
+include LICENSE
+include README.rst
+include requirements.txt
+
+recursive-exclude * __pycache__
+recursive-exclude * *.py[co]
+
+recursive-include docs *.rst conf.py Makefile make.bat
+
+include diffpy.snmf/version.py
+
+# If including data files in the package, add them like:
+# include path/to/data_file