The keybinding has changed from `SPC h l` to `SPC r l`; see the changelog, entry
0.200.0 (2016/10/02). So correct the documentation to reflect that.
`SPC h l` is currently bound to `helm-spacemacs-help-layers` (on branch
`develop`).
Add a README.org to the Helm layer to fix `helm-spacemacs-help-layers`
(`SPC h l`). There is little actual documentation -- it just links to
the official docs as well as the Helm wiki and the Helm guide.
Issue #8679