Bitcoin ABC version 0.20.0 is now available from:

  <https://download.bitcoinabc.org/0.20.0/>

This release includes the following features and fixes:

Bitcoin ABC version 0.20.0 is now available from:

  <https://download.bitcoinabc.org/0.20.0/>

This release includes the following features and fixes:
 - Support for Nov 2019 upgrade features, as detailed at https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/2019-11-15-upgrade.md
    - Schnorr signatures for OP_CHECKMULTISIG(VERIFY): https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/2019-11-15-schnorrmultisig.md
    - Enforce MINIMALDATA in script: https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/2019-11-15-minimaldata.md

Add upgrade features to release notes
Add upgrade features to release notes

Test Plan: Read it to make sure it makes sense.

Reviewers: markblundeberg, deadalnix, jasonbcox, Fabien, #bitcoin_abc

Reviewed By: Fabien, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3869
