docs: remove support issues and redirect to slack instead

Signed-off-by: Jan Larwig <jan.larwig@digits.schwarz>

.github/ISSUE_TEMPLATE/config.yml

@@ -1,6 +1,6 @@
 blank_issues_enabled: false
 contact_links:
-  - name: OAuth2 Proxy Slack
+  - name: Support & Community
     url: https://cloud-native.slack.com/archives/C098Y5URZ2N
-    about: Feel free to ask any questions here.
+    about: Feel free to ask any questions here. Be it configuration support. Contribution related or other. Invite Link: https://slack.cncf.io
 

.github/ISSUE_TEMPLATE/configuration-support.yml

@@ -1,61 +0,0 @@
-name: Configuration support
-description: Configuration problems and overall requests on how to properly use oauth2-proxy.
-title: "[Support]: <Short description>"
-labels: ["configuration", "help wanted"]
-body:
-  - type: input
-    attributes:
-      label: OAuth2-Proxy Version
-      description: Which version of oauth2-proxy are you using?
-    validations:
-      required: true
-  - type: dropdown
-    attributes:
-      label: Provider
-      description: Which identity provider are you using?
-      options:
-        - adfs
-        - azure
-        - bitbucket
-        - digitalocean
-        - entra-id
-        - facebook
-        - gitea
-        - github
-        - gitlab
-        - google
-        - keycloak
-        - keycloak-oidc
-        - linkedin
-        - logingov
-        - nextcloud
-        - oidc
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Current Behaviour of your Problem
-      description: Tell us what you expect to happen and what happens instead.
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Configuration details or additional information
-      description: |
-        Please share more details about your environment and how you configured oauth2-proxy.
-
-        Tip: You can attach images or log files by clicking this area to highlight it and then dragging files in.
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Steps To Reproduce
-      description: Steps to reproduce the behavior.
-      placeholder: |
-        1. In this environment...
-        1. With this config...
-        1. Run '...'
-        1. See error...
-    validations:
-      required: false
-