<<Amendment 1 21/09/18>>
Added functions to facilitate keybindings in derived layers consistent
with navigation style preference.
<<Amendment 2 24/09/18>>
Incorporated feedback from yyoncho
Corrected error in peek binding extension definition
<<Amendment 3 24/09/18>>
Moved 'heirarchy' prefix/keybindings from 'SPC m h' to 'SPC m <g/p> h' for
consistency with navigation style preference selections.
Added 'members' prefix under 'SPC m <g/p> m'
Moved 'lsp-ui-imenu' from 'SPC m g m' to 'SPC m g M'
<<Amendment 4 20/10/18>>
Rebased. Updated README formatting for consistency with norms.
<<Amendment 5 25/10/18>>
Rebased. Moved 'peek' keybindings from 'SPC m p' to 'SPC m G'
<<Amendment 6 01/11/18>>
Reased. Updated for compatibility with upstream changes in lsp-ui.
<<Amendment 7 02/11/18>>
Corrected oversight -- was still binding some peek funcs under 'p'
rather than 'G'. Moved backend keybindings to 'b' (for backend)
rather than 'l' (for lsp)
<<Amendment 8 06/11/18>>
Documentation corrections -- based on feedback from sdwolfz
18eacf48a2