chore: refresh PR/issue templates, labeler, and contributing docs

- bug_report.yml: drop the stale 'no v3 bug reports accepted' banner
  (v3 intake is the main workload); ask for the latest alpha tag and
  wails3 doctor output; mark the TS-generation note as v2-specific.
- pull_request_template.md: current alpha2 version example; document the
  v3/UNRELEASED_CHANGELOG.md wording-override alongside the automatic
  v3 changelog entries.
- issue-labeler.yml: 'master branch' no longer implies v2-only (v3 lives
  on master too).
- nightly-release-v3.yml: display name no longer references the retired
  v3-alpha branch.
- contributing.mdx: branch instructions said 'main'; the default branch
  is 'master'. Add the v3 changelog automation note.

Author: leaanthony

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -7,17 +7,15 @@ body:
   - type: markdown
     attributes:
       value: |
-        ***Please note: No bug reports are currently being accepted for Wails v3***
-        ***Please note: No bug reports are currently being accepted for Wails v3***
-        ***Please note: No bug reports are currently being accepted for Wails v3***
+        ***For Wails v3 bugs: please use the latest tagged alpha (e.g. `v3.0.0-alpha2.113`), not a source install, and include the output of `wails3 doctor`.***
         Before submitting this issue, please do the following:
         - Do a web search for your error. This usually leads to a much better understanding of the issue.
         - Prove that the error is indeed a Wails bug and not an application bug, with a specific set of steps to reproduce. 
         - Search the issue tracker using [this link](https://github.com/wailsapp/wails/issues?q=is%3Aissue+).
         - Search the [discussion forums](https://github.com/wailsapp/wails/discussions?discussions_q=type+your+issue+here).
         - Read the [Troubleshooting Guide](https://wails.io/docs/next/guides/troubleshooting).
         - Create a [Minimal Reproducible Example](https://stackoverflow.com/help/minimal-reproducible-example) and link to it in the issue.
-        - If your issue is related to TypeScript generation, please open a ticket and create a PR with a failing test case.
+        - (v2) If your issue is related to TypeScript generation, please open a ticket and create a PR with a failing test case.
         TS tests can be found [here](https://github.com/wailsapp/wails/tree/master/v2/internal/binding/binding_test). Remember to add
         your test to the `binding_test.go` file.
         - Try to fix it yourself. Keep a list of things you have done to fix the problem.   
@@ -75,7 +73,7 @@ body:
     id: systemdetails
     attributes:
       label: System Details
-      description: Please add the output of `wails doctor`.
+      description: Please add the output of `wails doctor` (v2) or `wails3 doctor` (v3).
       render: shell
     validations:
       required: true

.github/issue-labeler.yml

@@ -6,7 +6,6 @@ v2-only:
   - 'version 2'
   - 'wails v2'
   - 'using v2'
-  - 'master branch'
 
 v3-alpha:
   - '\[v3\]'

.github/pull_request_template.md

@@ -6,7 +6,7 @@
 *     YOUR PR MAY BE REJECTED IF IT DOES NOT FOLLOW THESE STEPS     *
 *********************************************************************
 
-- *DO NOT* submit bugs for a source install of v3, ONLY tagged versions, e.g. v3.0.0-alpha.11
+- *DO NOT* submit bugs for a source install of v3, ONLY tagged versions, e.g. v3.0.0-alpha2.113
 - *DO NOT* submit PRs for v3 alpha enhancements, unless you have opened a post on the discord channel.
   All enhancements must be discussed first.
   The feedback guide for v3 is here: https://v3.wails.io/feedback/
@@ -48,7 +48,7 @@ Please paste the output of `wails doctor`. If you are unable to run this command
 
 # Checklist:
 
-- [ ] (v2 only) I have updated `website/src/pages/changelog.mdx` with details of this PR (v3 changelog entries are added automatically)
+- [ ] (v2 only) I have updated `website/src/pages/changelog.mdx` with details of this PR (v3 changelog entries are added automatically on merge; to control the wording, add an entry to `v3/UNRELEASED_CHANGELOG.md`)
 - [ ] My code follows the general coding style of this project
 - [ ] I have performed a self-review of my own code
 - [ ] I have commented my code, particularly in hard-to-understand areas

.github/workflows/nightly-release-v3.yml

@@ -1,4 +1,4 @@
-name: Nightly Release v3-alpha
+name: Nightly Release v3
 
 on:
   schedule:

docs/src/content/docs/contributing.mdx

@@ -84,9 +84,9 @@ go test -cover ./...
 ### Create a Branch
 
 ```bash
-# Update main
-git checkout main
-git pull upstream main
+# Update master
+git checkout master
+git pull upstream master
 
 # Create feature branch
 git checkout -b feature/my-feature
@@ -100,6 +100,10 @@ git checkout -b feature/my-feature
 4. **Run tests** to ensure nothing breaks
 5. **Commit changes** with clear messages
 
+v3 changelog entries are generated automatically when your PR merges. To
+control the wording, add your own entry to `v3/UNRELEASED_CHANGELOG.md`
+and the automation will use it instead.
+
 ### Commit Guidelines
 
 ```bash