fix broken links in v4 as well

the [`4.x` branch](https://github.com/react-navigation/react-navigation/tree/4.x) has no issue templates or PR templates, but the latest 4.x tag, [v4.1.1](https://github.com/react-navigation/react-navigation/tree/v4.1.1), does

Author: agilgur5

versioned_docs/version-4.x/contributing.md

@@ -32,7 +32,7 @@ And here are a few helpful resources to aid in getting started:
 You can't write code without writing the occasional bug. Especially as React Navigation is moving quickly, bugs happen. When you think you've found one here's what to do:
 
 1. Search the existing issues for one like what you're seeing. If you see one, add a 👍 reaction (please no +1 comments). Read through the comments and see if you can provide any more valuable information to the thread
-2. If there are no other issues like yours then create a new one. Be sure to follow the [issue template](https://github.com/react-navigation/react-navigation/blob/4.x/.github/ISSUE_TEMPLATE.md).
+2. If there are no other issues like yours then create a new one. Be sure to follow the [issue template](https://github.com/react-navigation/react-navigation/blob/v4.1.1/.github/ISSUE_TEMPLATE/bug_report.md).
 
 Creating a high quality reproduction is critical. Without it we likely can't fix the bug and, in an ideal situation, you'll find out that it's not actually a bug of the library but simply done incorrectly in your project. Instant bug fix!
 
@@ -93,15 +93,15 @@ The libdef (located at `flow/react-navigation.js`) will need to be updated such
 
 ### Issue Template
 
-Before submitting an issue, please take a look at the [issue template](https://github.com/react-navigation/react-navigation/blob/4.x/.github/ISSUE_TEMPLATE.md) and follow it. This is in place to help everyone better understand the issue you're having and reduce the back and forth to get the necessary information.
+Before submitting an issue, please take a look at the [issue template](https://github.com/react-navigation/react-navigation/blob/v4.1.1/.github/ISSUE_TEMPLATE/bug_report.md) and follow it. This is in place to help everyone better understand the issue you're having and reduce the back and forth to get the necessary information.
 
 Yes, it takes time and effort to complete the issue template. But that's the only way to ask high quality questions that actually get responses.
 
 Would you rather take 1 minute to create an incomplete issue report and wait months to get any sort of response? Or would you rather take 20 minutes to fill out a high quality issue report, with all the necessary elements, and get a response in days? It's also a respectful thing to do for anyone willing to take the time to review your issue.
 
 ### Pull Request Template
 
-Much like the issue template, the [pull request template](https://github.com/react-navigation/react-navigation/blob/4.x/.github/PULL_REQUEST_TEMPLATE.md) lays out instructions to ensure your pull request gets reviewed in a timely manner and reduces the back and forth. Make sure to look it over before you start writing any code.
+Much like the issue template, the [pull request template](https://github.com/react-navigation/react-navigation/blob/v4.1.1/.github/PULL_REQUEST_TEMPLATE.md) lays out instructions to ensure your pull request gets reviewed in a timely manner and reduces the back and forth. Make sure to look it over before you start writing any code.
 
 ### Forking the Repository