Add CHANGES.md to generated packages

[dvberkel]

As addressed in #79 this pull-request adds CHANGES.md to the templates that get scaffolded on package creation.

A particular detail to be discussed is the content of the default CHANGES.md. Topics to form an opinion about include, but are not restricted to:

• The first version: currently set to 1.0.0
• The publication date: currently suggests a format as YYYY-MM-DD
• Include a suggested next version: currently the next version is X.Y.Z with a date TBD

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.32%. Comparing base (33027a6) to head (fef382c).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #84      +/-   ##
==========================================
+ Coverage   67.29%   67.32%   +0.03%     
==========================================
  Files           9        9              
  Lines        1006     1007       +1     
==========================================
+ Hits          677      678       +1     
  Misses        329      329              

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