Lobster needs special handling of the ⟨Ḷḷ⟩ digraph

**Describe the bug**
Even though Lobster is one of the few fonts in the Google Fonts catalog that fully supports the Asturian language by providing underdotted H and L, writing words that have the combination ⟨Ḷḷ⟩ such as the place name _Ḷḷena_ results in a muddy appearance, as the tail of the L almost completely obscures the underdot in the lowercase ell. A contextual feature or automatic ligature would be great.