creat migration guide for version 1.0.28#445

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fischerscode merged 7 commits intoparse-community:release/1.0.28from

fischerscode:create-migrate-guide

Oct 2, 2020

Commits on Sep 17, 2020

fix typos
fischerscode
committed

Commits on Oct 2, 2020

added "changed network library" to migration guide
fischerscode
committed