* Fix double slash in index path

Double slash might disturb comparison and make them false positive.

* Fix compatibility with older fish shell

Suggested by @faho [here](https://github.com/oh-my-fish/oh-my-fish/pull/775#issuecomment-736224485).

For example, "git diff" would print
"fatal: this operation must be run in a work tree"

We could still run git_branch_name in bare repositories in future.

Some git commands require to be run from inside the worktree (as opposed
    to the git dir, although it's usually in .git). This commit adds
a function git_is_worktree to check this. It is used for the commands
that need the worktree instead of git_is_repo.

An alternative solution might have been to find the git worktree in the
parent of the git directory, but this doesn't work for all cases.
Generally it's impossible to detect the location of the worktree (plus
    it's not unique).
Co-authored-by: Pablo Aguiar <scorphus@gmail.com>

Fix bug when creating new theme

Add missing links, reorder alphabetically, and fix spacing issues.

Note that this includes a little bit of manual deduplication, as we have several contributors who have used different names for the same email address (or different email addresses for the same name?). Future updates to this list will need to manually dedupe as well.

Fixes #738 by changing the git config autocrlf test to check for what we do not want to see "false".

Instead of trying to convert the output of git config autocrlf to binary, which will not always work as "input" is also a valid value in addition to true and false, we check for the value false and exit if it is found.

- Make logo.png 1024x1024 as originally intended
- Apply lossless compression (now 10k instead of 17k)
- Normalize logo.svg's viewbox, which probably caused the incorrectly sized logo.png in the first place

Fixes #737

Fix some typos in Spanish README

fix one more caret error