Fix broken links to Gitter Community (Fixes: #8197) (#8546)

Co-authored-by: Christian Clauss <cclauss@me.com>

.github/stale.yml

@@ -45,7 +45,7 @@ pulls:
   closeComment: >
     Please reopen this pull request once you commit the changes requested
     or make improvements on the code. If this is not the case and you need
-    some help, feel free to seek help from our [Gitter](https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im)
+    some help, feel free to seek help from our [Gitter](https://gitter.im/TheAlgorithms/community)
     or ping one of the reviewers. Thank you for your contributions!
 
 issues:
@@ -59,5 +59,5 @@ issues:
   closeComment: >
     Please reopen this issue once you add more information and updates here.
     If this is not the case and you need some help, feel free to seek help
-    from our [Gitter](https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im) or ping one of the
+    from our [Gitter](https://gitter.im/TheAlgorithms/community) or ping one of the
     reviewers. Thank you for your contributions!

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 ## Before contributing
 
-Welcome to [TheAlgorithms/Python](https://github.com/TheAlgorithms/Python)! Before sending your pull requests, make sure that you __read the whole guidelines__. If you have any doubt on the contributing guide, please feel free to [state it clearly in an issue](https://github.com/TheAlgorithms/Python/issues/new) or ask the community in [Gitter](https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im).
+Welcome to [TheAlgorithms/Python](https://github.com/TheAlgorithms/Python)! Before sending your pull requests, make sure that you __read the whole guidelines__. If you have any doubt on the contributing guide, please feel free to [state it clearly in an issue](https://github.com/TheAlgorithms/Python/issues/new) or ask the community in [Gitter](https://gitter.im/TheAlgorithms/community).
 
 ## Contributing
 
@@ -176,7 +176,7 @@ We want your work to be readable by others; therefore, we encourage you to note
 
 - Most importantly,
   - __Be consistent in the use of these guidelines when submitting.__
-  - __Join__ us on [Discord](https://discord.com/invite/c7MnfGFGa6) and [Gitter](https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im) __now!__
+  - __Join__ us on [Discord](https://discord.com/invite/c7MnfGFGa6) and [Gitter](https://gitter.im/TheAlgorithms/community) __now!__
   - Happy coding!
 
 Writer [@poyea](https://github.com/poyea), Jun 2019.

README.md

@@ -16,7 +16,7 @@
   <a href="https://discord.gg/c7MnfGFGa6">
     <img src="https://img.shields.io/discord/808045925556682782.svg?logo=discord&colorB=7289DA&style=flat-square" height="20" alt="Discord chat">
   </a>
-  <a href="https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im">
+  <a href="https://gitter.im/TheAlgorithms/community">
     <img src="https://img.shields.io/badge/Chat-Gitter-ff69b4.svg?label=Chat&logo=gitter&style=flat-square" height="20" alt="Gitter chat">
   </a>
   <!-- Second row: -->
@@ -42,7 +42,7 @@ Read through our [Contribution Guidelines](CONTRIBUTING.md) before you contribut
 
 ## Community Channels
 
-We are on [Discord](https://discord.gg/c7MnfGFGa6) and [Gitter](https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im)! Community channels are a great way for you to ask questions and get help. Please join us!
+We are on [Discord](https://discord.gg/c7MnfGFGa6) and [Gitter](https://gitter.im/TheAlgorithms/community)! Community channels are a great way for you to ask questions and get help. Please join us!
 
 ## List of Algorithms
 

project_euler/README.md

@@ -10,7 +10,7 @@ The solutions will be checked by our [automated testing on GitHub Actions](https
 
 ## Solution Guidelines
 
-Welcome to [TheAlgorithms/Python](https://github.com/TheAlgorithms/Python)! Before reading the solution guidelines, make sure you read the whole [Contributing Guidelines](https://github.com/TheAlgorithms/Python/blob/master/CONTRIBUTING.md) as it won't be repeated in here. If you have any doubt on the guidelines, please feel free to [state it clearly in an issue](https://github.com/TheAlgorithms/Python/issues/new) or ask the community in [Gitter](https://app.gitter.im/#/room/#TheAlgorithms_community:gitter.im). You can use the [template](https://github.com/TheAlgorithms/Python/blob/master/project_euler/README.md#solution-template) we have provided below as your starting point but be sure to read the [Coding Style](https://github.com/TheAlgorithms/Python/blob/master/project_euler/README.md#coding-style) part first.
+Welcome to [TheAlgorithms/Python](https://github.com/TheAlgorithms/Python)! Before reading the solution guidelines, make sure you read the whole [Contributing Guidelines](https://github.com/TheAlgorithms/Python/blob/master/CONTRIBUTING.md) as it won't be repeated in here. If you have any doubt on the guidelines, please feel free to [state it clearly in an issue](https://github.com/TheAlgorithms/Python/issues/new) or ask the community in [Gitter](https://gitter.im/TheAlgorithms/community). You can use the [template](https://github.com/TheAlgorithms/Python/blob/master/project_euler/README.md#solution-template) we have provided below as your starting point but be sure to read the [Coding Style](https://github.com/TheAlgorithms/Python/blob/master/project_euler/README.md#coding-style) part first.
 
 ### Coding Style