Fix references to the old master branch with the new branch name

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,11 +2,11 @@ Thank you for taking time to contribute this pull request!
 You might have already read the [contributor guide][1], but as a reminder, please make sure to:
 
 * Sign the [contributor license agreement](https://cla.pivotal.io/sign/spring)
-* Rebase your changes on the latest `master` branch and squash your commits
+* Rebase your changes on the latest `main` branch and squash your commits
 * Add/Update unit tests as needed
 * Run a build and make sure all tests pass prior to submission
 
 For more details, please check the [contributor guide][1].
 Thank you upfront!
 
-[1]: https://github.com/spring-projects/spring-batch/blob/master/CONTRIBUTING.md
+[1]: https://github.com/spring-projects/spring-batch/blob/main/CONTRIBUTING.md

README.md

@@ -6,7 +6,7 @@ If you are looking for a runtime orchestration tool for your Batch applications,
 
 ## Code of Conduct
 
-Please see our [code of conduct](https://github.com/spring-projects/.github/blob/master/CODE_OF_CONDUCT.md).
+Please see our [code of conduct](https://github.com/spring-projects/.github/blob/main/CODE_OF_CONDUCT.md).
 
 ## Reporting Security Vulnerabilities
 
@@ -91,7 +91,7 @@ Here are some ways for you to get involved in the community:
 
 * Get involved with the Spring Batch community on [Twitter](https://twitter.com/springbatch) and [StackOverflow](https://stackoverflow.com/questions/tagged/spring-batch) by responding to questions and joining the debate.
 * Create [issues](https://github.com/spring-projects/spring-batch/issues) for bugs and new features and comment and vote on the ones that you are interested in.
-* Github is for social coding: if you want to write code, we encourage contributions through pull requests from [forks of this repository](https://help.github.com/forking/).  If you want to contribute code this way, please familiarize yourself with the process outlined for contributing to Spring projects here: [Contributor Guidelines](https://github.com/spring-projects/spring-batch/blob/master/CONTRIBUTING.md).
+* Github is for social coding: if you want to write code, we encourage contributions through pull requests from [forks of this repository](https://help.github.com/forking/).  If you want to contribute code this way, please familiarize yourself with the process outlined for contributing to Spring projects here: [Contributor Guidelines](https://github.com/spring-projects/spring-batch/blob/main/CONTRIBUTING.md).
 * Watch for upcoming articles on Spring by [subscribing](feed://assets.spring.io/drupal/node/feed.xml) to [spring.io](https://spring.io).
 
 Before we accept a non-trivial patch or pull request we will need you to sign the [contributor's agreement](https://support.springsource.com/spring_committer_signup).  Signing the contributor's agreement does not grant anyone commit rights to the main repository, but it does mean that we can accept your contributions, and you will get an author credit if we do.  Active contributors might be asked to join the core team, and given the ability to merge pull requests.

spring-batch-docs/src/main/asciidoc/scalability.adoc

@@ -129,7 +129,7 @@ usable in a multi-threaded `Step`. In particular, most of the off-the-shelf read
 writers from Spring Batch are not designed for multi-threaded use. It is, however,
 possible to work with stateless or thread safe readers and writers, and there is a sample
 (called `parallelJob`) in the
-https://github.com/spring-projects/spring-batch/tree/master/spring-batch-samples[Spring
+https://github.com/spring-projects/spring-batch/tree/main/spring-batch-samples[Spring
 Batch Samples] that shows the use of a process indicator (see
 <<readersAndWriters.adoc#process-indicator,Preventing State Persistence>>) to keep track
 of items that have been processed in a database input table.
@@ -330,7 +330,7 @@ attribute prevents the task executor from being saturated with requests from a s
 step.
 
 There is a simple example that can be copied and extended in the unit test suite for
-https://github.com/spring-projects/spring-batch/tree/master/spring-batch-samples/src/main/resources/jobs[Spring
+https://github.com/spring-projects/spring-batch/tree/main/spring-batch-samples/src/main/resources/jobs[Spring
 Batch Samples] (see `partition*Job.xml` configuration).
 
 Spring Batch creates step executions for the partitions called "step1:partition0", and so

spring-batch-docs/src/main/asciidoc/spring-batch-integration.adoc

@@ -1032,7 +1032,7 @@ public class RemoteChunkingJobConfiguration {
 ----
 
 You can find a complete example of a remote chunking job
-link:$$https://github.com/spring-projects/spring-batch/tree/master/spring-batch-samples#remote-chunking-sample$$[here].
+link:$$https://github.com/spring-projects/spring-batch/tree/main/spring-batch-samples#remote-chunking-sample$$[here].
 
 [[remote-partitioning]]
 

spring-batch-docs/src/main/asciidoc/step.adoc

@@ -1373,7 +1373,7 @@ order to set up various resources or after processing has completed to cleanup t
 resources. In the case of a job that works heavily with files, it is often necessary to
 delete certain files locally after they have been uploaded successfully to another
 location. The following example (taken from the
-https://github.com/spring-projects/spring-batch/tree/master/spring-batch-samples[Spring
+https://github.com/spring-projects/spring-batch/tree/main/spring-batch-samples[Spring
 Batch samples project]) is a `Tasklet` implementation with just such a responsibility:
 
 [source, java]