docs: link to github discussions, stackoverflow instead of discourse

.github/ISSUE_TEMPLATE/config.yml

@@ -1,6 +1,5 @@
 blank_issues_enabled: false
 contact_links:
    - name: Question
-     url: https://neovim.discourse.group/c/language-server-protocol-lsp/7
-     about: Usage questions and support requests are answered in the Neovim Discourse
-
+     url: https://vi.stackexchange.com/
+     about: Usage questions and support requests

README.md

@@ -143,7 +143,7 @@ a new configuration for it helps others, especially if the server requires speci
     - Copy an [existing config](https://github.com/neovim/nvim-lspconfig/blob/master/lua/lspconfig/server_configurations/)
       to get started. Most configs are simple. For an extensive example see
       [texlab.lua](https://github.com/neovim/nvim-lspconfig/blob/master/lua/lspconfig/server_configurations/texlab.lua).
-3. Ask questions on our [Discourse](https://neovim.discourse.group/c/7-category/7) or in the [Neovim Matrix room](https://app.element.io/#/room/#neovim:matrix.org).
+3. Ask questions on [GitHub Discussions](https://github.com/neovim/neovim/discussions) or in the [Neovim Matrix room](https://app.element.io/#/room/#neovim:matrix.org).
 
 ### Release process