chore: prepare pipelines and docs for renaming main branch

Author: kangasta

.github/workflows/test.yaml

@@ -32,11 +32,11 @@ jobs:
       run: make lint
 
     - name: Test PR
-      if: github.ref != 'refs/heads/master'
+      if: github.ref != 'refs/heads/main'
       run: make test
 
-    - name: Test Master
-      if: github.ref == 'refs/heads/master'
+    - name: Test main
+      if: github.ref == 'refs/heads/main'
       env:
           UPCLOUD_API_USER: ${{ secrets.UPCLOUD_API_USER }}
           UPCLOUD_API_PASSWORD: ${{ secrets.UPCLOUD_API_PASSWORD }}

docs-src/builders/upcloud.mdx

@@ -46,7 +46,7 @@ The upcloud builder is used to generate storage templates on UpCloud.
 -->
 ### Example Usage
 
-Here is a sample template, which you can also find in the [example](https://github.com/UpCloudLtd/packer-plugin-upcloud/tree/master/example) directory.  
+Here is a sample template, which you can also find in the [example](https://github.com/UpCloudLtd/packer-plugin-upcloud/tree/main/example) directory.
 It reads your UpCloud API credentials from the environment variables, creates an Ubuntu 20.04 LTS server in the `nl-ams1` region and authorizes root user to loggin with your public SSH key.
 
 ```hcl