C-h and C-l mappings in the documentation

[carlotrimarchi]

Just a suggestion: why don't you put C-h and C-l, the commands to modify the size of the main panel, in the readme file? And also the instructions to remap those. I think they conflict with many other commonly used Vim mappings and it would be useful to know right away how to remap them.

[spolu]

@carlotrimarchi make sense. I think they were added later on. I'd be happy to merge any pull request relative to that!