(chocolatey#2231) Change default repository URL

As part of the community changes for our web infrastructure, the default
repository URL is now community.chocolatey.org/api/v2/ rather than
chocolatey.org/api/v2/, so all places where the old URL is used has been
updated.  There are redirects in place for this, but it makes sense for
the source to updated to reflect the actual URL.

src/chocolatey/infrastructure.app/commands/ChocolateyHelpCommand.cs

@@ -245,7 +245,7 @@ continue without requiring any action after the temporary timeout
    upgrade or install (unless switched off explicitly).
  * If you are sharing the script with others, pass `--source` to be
    explicit about where the package is coming from. Use full link and
-   not source name ('https://chocolatey.org/api/v2' versus
+   not source name ('https://community.chocolatey.org/api/v2' versus
    'chocolatey').
  * If parsing output, you might want to use `--limit-output`/`-r` to
    get output in a more machine parseable format. NOTE: Not all
@@ -268,7 +268,7 @@ Now here is that example written with best practices (again line
  breaks added for readability - there are not line continuations
  for choco):
 
-  `choco upgrade pkg1 -y --source=""'https://chocolatey.org/api/v2'""
+  `choco upgrade pkg1 -y --source=""'https://community.chocolatey.org/api/v2'""
    --package-parameters=""'/Option:Value /Option2:value with spaces'""
    --c4b-option=""'Yaass'"" --option-that-is-new=""'dude upgrade'""`