Align overwriting of get_queryset in example app and documentation

[sliverc]

Fixes #487

Description of the Change

Make sure that in example app local queryset is used for filtering.

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added
• documentation updated
• CHANGELOG.md updated (only for user relevant changes)
• author name in AUTHORS

[codecov]

Codecov Report

Merging #979 (83b3516) into master (f8209c0) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #979   +/-   ##
=======================================
  Coverage   96.82%   96.82%           
=======================================
  Files          65       65           
  Lines        3904     3904           
=======================================
  Hits         3780     3780           
  Misses        124      124           

Impacted Files	Coverage Δ
example/views.py	94.21% <100.00%> (ø)

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