Update "master" branch references to "main"

Update "master" branch references to "main".

Signed-off-by: David Enyeart <enyeart@us.ibm.com>

MAINTAINERS.md

@@ -15,6 +15,6 @@ fabric-samples uses a non-author code review policy, requiring a single approval
 | Nikhil Gupta              | nikhil550        | negupta        | nikhilg550@gmail.com                |
 | Simon Stone               | sstone1          | sstone1        | sstone1@uk.ibm.com                  |
 
-Also: Please see the [Release Manager section](https://github.com/hyperledger/fabric/blob/master/MAINTAINERS.md)
+Also: Please see the [Release Manager section](https://github.com/hyperledger/fabric/blob/main/MAINTAINERS.md)
 
 <a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>.

README.md

@@ -28,7 +28,7 @@ transfer an asset in a more realistic transfer scenario.
 | [Basic](asset-transfer-basic) | The Basic sample smart contract that allows you to create and transfer an asset by putting data on the ledger and retrieving it. This sample is recommended for new Fabric users. | [Writing your first application](https://hyperledger-fabric.readthedocs.io/en/latest/write_first_app.html) | Go, JavaScript, TypeScript, Java | Go, JavaScript, TypeScript, Java |
 | [Ledger queries](asset-transfer-ledger-queries) | The ledger queries sample demonstrates range queries and transaction updates using range queries (applicable for both LevelDB and CouchDB state databases), and how to deploy an index with your chaincode to support JSON queries (applicable for CouchDB state database only). | [Using CouchDB](https://hyperledger-fabric.readthedocs.io/en/latest/couchdb_tutorial.html) | Go, JavaScript | Java, JavaScript |
 | [Private data](asset-transfer-private-data) | This sample demonstrates the use of private data collections, how to manage private data collections with the chaincode lifecycle, and how the private data hash can be used to verify private data on the ledger. It also demonstrates how to control asset updates and transfers using client-based ownership and access control. | [Using Private Data](https://hyperledger-fabric.readthedocs.io/en/latest/private_data_tutorial.html) | Go, Java | JavaScript |
-| [State-Based Endorsement](asset-transfer-sbe) | This sample demonstrates how to override the chaincode-level endorsement policy to set endorsement policies at the key-level (data/asset level). | [Using State-based endorsement](https://github.com/hyperledger/fabric-samples/tree/master/asset-transfer-sbe) | Java, TypeScript | JavaScript |
+| [State-Based Endorsement](asset-transfer-sbe) | This sample demonstrates how to override the chaincode-level endorsement policy to set endorsement policies at the key-level (data/asset level). | [Using State-based endorsement](https://github.com/hyperledger/fabric-samples/tree/main/asset-transfer-sbe) | Java, TypeScript | JavaScript |
 | [Secured agreement](asset-transfer-secured-agreement) | Smart contract that uses implicit private data collections, state-based endorsement, and organization-based ownership and access control to keep data private and securely transfer an asset with the consent of both the current owner and buyer. | [Secured asset transfer](https://hyperledger-fabric.readthedocs.io/en/latest/secured_asset_transfer/secured_private_asset_transfer_tutorial.html)  | Go | JavaScript |
 | [Events](asset-transfer-events) | The events sample demonstrates how smart contracts can emit events that are read by the applications interacting with the network. | [README](asset-transfer-events/README.md)  | JavaScript, Java | JavaScript |
 | [Attribute-based access control](asset-transfer-abac) | Demonstrates the use of attribute and identity based access control using a simple asset transfer scenario | [README](asset-transfer-abac/README.md)  | Go | None |

ci/azure-pipelines.yml

@@ -3,7 +3,7 @@
 #
 
 trigger:
-  - master
+  - main
   - release-1.4
 
 variables:

off_chain_data/README.md

@@ -1,6 +1,6 @@
 # Off Chain data
 
-This sample demonstrates how you can use [Peer channel-based event services](https://hyperledger-fabric.readthedocs.io/en/master/peer_event_services.html)
+This sample demonstrates how you can use [Peer channel-based event services](https://hyperledger-fabric.readthedocs.io/en/latest/peer_event_services.html)
 to replicate the data on your blockchain network to an off chain database.
 Using an off chain database allows you to analyze the data from your network or
 build a dashboard without degrading the performance of your application.