feat!: change default mappings for preview

Home/End/Up/Down/Left/Right are usually used to moving cursor in Command
mode so we should keep it otherwise users won't be able to move cursor.

Author: lambdalisue

plugin/fall/mapping.vim

@@ -70,14 +70,14 @@ if !get(g:, 'fall_disable_default_mapping')
     cnoremap <nowait> <C-j> <Plug>(fall-select)<Plug>(fall-next)
     cnoremap <nowait> <C-k> <Plug>(fall-prev)<Plug>(fall-select)
     " Preview
-    cnoremap <nowait> <Home> <Plug>(fall-preview-first)
-    cnoremap <nowait> <End> <Plug>(fall-preview-last)
-    cnoremap <nowait> <Up> <Plug>(fall-preview-prev)
-    cnoremap <nowait> <Down> <Plug>(fall-preview-next)
+    cnoremap <nowait> <M-Home> <Plug>(fall-preview-first)
+    cnoremap <nowait> <M-End> <Plug>(fall-preview-last)
+    cnoremap <nowait> <M-Up> <Plug>(fall-preview-prev)
+    cnoremap <nowait> <M-Down> <Plug>(fall-preview-next)
     cnoremap <nowait> <S-Up> <Plug>(fall-preview-prev:scroll)
     cnoremap <nowait> <S-Down> <Plug>(fall-preview-next:scroll)
-    cnoremap <nowait> <Left> <Plug>(fall-preview-left)
-    cnoremap <nowait> <Right> <Plug>(fall-preview-right)
+    cnoremap <nowait> <M-Left> <Plug>(fall-preview-left)
+    cnoremap <nowait> <M-Right> <Plug>(fall-preview-right)
     cnoremap <nowait> <S-Left> <Plug>(fall-preview-left:scroll)
     cnoremap <nowait> <S-Right> <Plug>(fall-preview-right:scroll)
     " Action