Propose renaming the repo

[matthewberryman]

While #3 addresses the rename more fully in the docs, oh-my-zsh gets confused (breaks the plugin) if the directory name doesn't match the name of the plugin file. E.g.

cd ~/.oh-my-zsh/custom/plugins
git clone https://github.com/DarrinTisdale/zsh-aliases-exa.git

with plugins=(zsh-aliases-eza ... or the older plugins=(zsh-aliases-exa..., whereas:

cd ~/.oh-my-zsh/custom/plugins
git clone https://github.com/DarrinTisdale/zsh-aliases-exa.git zsh-aliases-eza

works with plugins=(zsh-aliases-eza ... as now documented in #3

I propose renaming the repo to zsh-aliases-eza (github will setup an automatic redirect from the old name), which fixes the issue.