[request] group program specific bindings

The syntax to have program specific bindings is
````
[
"" :
"" :
]
````
if one has a lot of keybindings specific to one single application this can take up a lot of space in the config file.

I'd be nice to be able to use the following syntax
````
[
:
:
]
````

The issue proposes grouping program-specific key bindings in the configuration syntax, but it names no implementation files, tests, or entry points. First locate the configuration parser and existing program-specific binding handling, then determine how the grouped form should be parsed and validated. Done means the proposed syntax works without changing existing binding behavior and is covered by tests.

Written by the indexing model from the issue text.