docs: allow blank issues and drop stale Submit-a-Server reference (#115)

Two follow-ups that were part of PR #114's branch but did not make it
into the squash merge:

- `.github/ISSUE_TEMPLATE/config.yml` — flip `blank_issues_enabled`
  from `false` to `true` so anyone (not just maintainers) can open a
  blank issue from the "New issue" chooser. Without the flag, non-
  maintainers only see the structured templates.
- `.github/ISSUE_TEMPLATE/request-server.yml` — replace the outdated
  "use the Submit a Server template (or open a PR)" hint. The
  Submit-a-Server template was removed in the prior PR because issue
  forms can't create PRs; repoint readers straight at CONTRIBUTING.md's
  quickstart instead.

Signed-off-by: Mohammod Al Amin Ashik <maa.ashik00@gmail.com>

Author: its-mash

.github/ISSUE_TEMPLATE/config.yml

@@ -1,4 +1,4 @@
-blank_issues_enabled: false
+blank_issues_enabled: true
 contact_links:
   - name: Contributing Guide (Pull Request path)
     url: https://github.com/mcpmux/mcp-servers/blob/main/CONTRIBUTING.md

.github/ISSUE_TEMPLATE/request-server.yml

@@ -8,7 +8,7 @@ body:
       value: |
         Know of an MCP server that should be in the McpMux registry? Tell us about it here.
 
-        If you already have a working definition, use the **Submit a Server** template (or open a PR) instead — that's the fastest path.
+        If you already have a working definition, **open a Pull Request** instead — that's the fastest path. See [CONTRIBUTING.md](https://github.com/mcpmux/mcp-servers/blob/main/CONTRIBUTING.md) for the five-command quickstart.
 
   - type: input
     id: name