Support for indented tables

[pbsds]

This plugin doesn't recognize tables that has been indented. My current workflow consists of deindenting the table to work on it before indenting it again.

This is needed in the case where you add table inside of a list

[susisu]

markdown-table-editor relies on language-* packages to find tables, but unfortunately indented tables are not recognized by some of those packages. Setting scope to source.gfm (for language-gfm) or text.md (for language-markdown) is a quick fix for your problem, but please note that it may cause misrecognition of tables.