update docs content (#11374)

Move all docs to zed repo

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
Co-authored-by: Marshall <marshall@zed.dev>

docs/book.toml

@@ -11,3 +11,9 @@ no-section-label = true
 
 [output.html.print]
 enable = false
+
+[output.html.redirect]
+"/elixir" = "languages/elixir"
+"/javascript" = "languages/javascript"
+"/ruby" = "languages/ruby"
+"/python" = "languages/python"