Tweak scope of symbols-tree-view and minimap Atom keymappings.
Tweak scope of symbols-tree-view and minimap Atom keymappings.

Prior to this commit, the `,`-prefixed mappings behave inconsistently,
sometimes not triggering the command at all.

- `atom-workspace` for symbols-tree-view reflects what is used in the
  package's keymaps.
- `not(.insert-mode)` for minimap reflects the seemingly most
  appropriate given the keymappings in the vim-mode package.

alphabetum/dotfiles,alphabetum/dotfiles,alphabetum/dotfiles,alphabetum/dotfiles