Add documentation on pagination with custom resource managers [ci skip]
Fix QueryBuilderPageDescription to actually get a slice, not only the count

A QueryBuilder is mutable, so when getTotalItemCount() is executed, its select statement gets changed to COUNT(%s). When getSlice() gets called after that, select still is COUNT(%s) instead of the desired entity
Merge branch 'feature/pagination-take-2' into develop

* feature/pagination-take-2:
  Fix QueryBuilderPageDescription to actually get a slice, not only the count
  Add documentation on pagination with custom resource managers [ci skip]
Revert "Update readme.md s/develop/master/ [ci skip]"

This reverts commit 4b11ef3217e3346ffe8f9dcfb153d3e8c68b1198.