Discord links have been removed (#2110)

Author: dbazhenov

.github/ISSUE_TEMPLATE/config.yml

@@ -1,8 +1,5 @@
 blank_issues_enabled: false
 contact_links:
-  - name: Discord
-    url: https://per.co.na/discord
-    about: Please join our discord for quick questions.
   - name: Forum
     url: https://forums.percona.com/
     about: Please join our forums for general questions ans discussions.

CONTRIBUTING.md

@@ -221,4 +221,4 @@ For more efficient review process we use a mixed approach:
 
 Once your pull request is merged, you are an official Percona Community Contributor. Welcome to the community!
 
-We're looking forward to your contributions and hope to hear from you soon on our [Forums](https://forums.percona.com) and [Discord](https://discord.gg/mQEyGPkNbR).
+We're looking forward to your contributions and hope to hear from you soon on our [Forums](https://forums.percona.com).

README.md

@@ -4,7 +4,6 @@
 [![CLA assistant](https://cla-assistant.percona.com/readme/badge/percona/pmm)](https://cla-assistant.percona.com/percona/pmm)
 [![Code coverage](https://codecov.io/gh/percona/pmm/branch/main/graph/badge.svg)](https://codecov.io/gh/percona/pmm)
 [![Go Report Card](https://goreportcard.com/badge/github.com/percona/pmm)](https://goreportcard.com/report/github.com/percona/pmm)
-[![Discord](https://img.shields.io/discord/808660945513611334?label=Discord&logo=Discord&style=flat)](https://per.co.na/discord)
 [![Forum](https://img.shields.io/badge/Forum-join-brightgreen)](https://forums.percona.com/)
 
 ![PMM](img/pmm-logo.png)
@@ -76,7 +75,7 @@ We encourage contributions and are always looking for new members that are as de
 
 If you’re looking for information about how you can contribute, we have [contribution guidelines](CONTRIBUTING.md) across all our repositories in `CONTRIBUTING.md` files. Some of them may just link to the main project’s repository’s contribution guidelines.
 
-We're looking forward to your contributions and hope to hear from you soon on our [Forums](https://forums.percona.com) and [Discord](https://per.co.na/discord).
+We're looking forward to your contributions and hope to hear from you soon on our [Forums](https://forums.percona.com).
 
 ## Submitting Bug Reports