Updates for _gitconfig.

    * Improve colors for Git.
    * Set git-diff algorithm.
(Vim) Default fileformats.
(Vim) Fine configs for editing.

    * Relative line number with toggler to absolute.
    * Scroll margin.
(Vim) Fine visual configs.

    * Keymap to echo full-path for Vim.
    * Tab to show matching brackets in normal mode.