chore: replace master with main wherever possible (aws#20590)

* chore: replace master with main wherever possible

* update amplify tests

* fix iconurl

* monocdk main

Co-authored-by: Kendra Neil <[email protected]>

Author: kaizencc

.github/PULL_REQUEST_TEMPLATE.md

@@ -3,15 +3,15 @@
 
 ### All Submissions:
 
-* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md)
+* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md)
 
 ### Adding new Unconventional Dependencies:
 
-* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md/#adding-new-unconventional-dependencies)
+* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md/#adding-new-unconventional-dependencies)
 
 ### New Features
 
-* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
+* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/main/INTEGRATION_TESTS.md)?
 	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?
 
 *By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

.github/workflows/cr-mapping.json

@@ -2,7 +2,7 @@
   "mappings": [
     {
       "keywords": ["CustomResourceProvider", "CustomResource", "CloudFormationCustomResourceDeleteEvent", "CloudFormationCustomResourceUpdateEvent", "CloudFormationCustomResourceCreateEvent"],
-      "comment": "I have read the guidelines on the [important cases to handle](https://github.com/aws/aws-cdk/tree/master/packages/%40aws-cdk/custom-resources#important-cases-to-handle) when implementing the custom resource."
+      "comment": "I have read the guidelines on the [important cases to handle](https://github.com/aws/aws-cdk/tree/main/packages/%40aws-cdk/custom-resources#important-cases-to-handle) when implementing the custom resource."
     }
   ]
 }