Remove 404 links

`dimitardimitrov/radium` and `omBratteng/zsh-plugin-pipx` are both 404, remove.

Signed-off-by: Joe Block <[email protected]>

Author: unixorn

README.md

@@ -1493,7 +1493,6 @@ These plugins add tab completions without adding extra functions or aliases.
 - [pip-completion](https://github.com/srijanshetty/zsh-pip-completion) - Autocompletion plugin for pip.
 - [pipenv (AlexGascon)](https://github.com/AlexGascon/pipenv-oh-my-zsh) - Enables aliases for the most common pipenv commands.
 - [pipenv (gangleri)](https://github.com/gangleri/pipenv) - Completions for `pipenv`.
-- [pipx](https://github.com/omBratteng/zsh-plugin-pipx) - Tab completions for [pipx](https://github.com/pypa/pipx).
 - [pks-autocomplete](https://github.com/tybritten/pks-zsh-autocomplete-plugin) - Adds completions for Pivotal's [PKS CLI](https://network.pivotal.io/products/pivotal-container-service)
 - [pmy](https://github.com/relastle/pmy) - General purpose context-aware ZSH completion engine powered by [fzf](https://github.com/junegunn/fzf).
 - [poetry](https://github.com/fourdim/zsh-poetry) - Tab completions for [poetry](https://python-poetry.org/).
@@ -2185,7 +2184,6 @@ If you're using [Antigen](https://github.com/zsh-users/antigen), you can test th
 - [quewui](https://github.com/kauefontes/oh-my-quewui) - Simple and clean theme optimized for dark terminal themes. Includes decorations for the current time, user, directory and `git` status.
 - [r3nic1e](https://github.com/r3nic1e/r3nic1e) - [Agnoster](https://github.com/agnoster/agnoster-zsh-theme) variant with battery status, `git/hg` status, time, kubernetes context and namespace, non-zero exit code of last command and date decorations. Requires Powerline font.
 - [racotecnic](https://github.com/elboletaire/zsh-theme-racotecnic) - Based on af-magic and posh-git.
-- [radium](https://github.com/dimitardimitrov/radium) - Designed for dark terminals, (works best with [Solarized](https://github.com/altercation/solarized) iTerm 2 theme) (prezto).
 - [radius](https://github.com/erikcc02/radius-zsh-theme) - Includes `git` status, username, hostname, and directory decorations, plus [desk](https://github.com/jamesob/desk) support.
 - [rafiki](https://github.com/akabiru/rafiki-zsh) - Adds emojis to your ZSH terminal.
 - [ramiel](https://github.com/aknackd/zsh-themes) - Fork of the [node](https://github.com/skuridin/oh-my-zsh-node-theme).