docs(integrations): github app name must not contain any spaces

Closes getsentry/self-hosted#3509

Author: aldy505

develop-docs/integrations/github.mdx

@@ -5,10 +5,10 @@ sidebar_title: GitHub
 
 ## Create a GitHub App
 
-To configure the GitHub integration you'll need to create a GitHub app and obtain credentials.
+To configure the GitHub integration you'll need to create a GitHub app and obtain credentials. Installation will fail if your Github App's name contains spaces.
 
 <Alert level="warning">
-  The GitHub Org Slug must not contain any spaces.
+  The GitHub App name and GitHub Org Slug must not contain any spaces.
 </Alert>
 
 <CreateGitHubAppForm url="https://github.com/organizations/:org/settings/apps/new?name=:org-Sentry-Integration&public=false&members=read&emails=read&administration=read&contents=read&issues=write&pull_requests=write&repository_hooks=write&url=:url-prefix&callback_url=:url-prefix%2Fauth%2Fsso%2F&setup_url=:url-prefix%2Fextensions%2Fgithub%2Fsetup%2F&webhook_url=:url-prefix%2Fextensions%2Fgithub%2Fwebhook%2F&events[]=push&events[]=pull_request&webhook_active=true" defaultOrg="your-organization" defaultUrlPrefix="https://your-sentry-url-prefix.com" />