Added class and os alternates

.oh-my-zsh/plugins/httpie/README.md

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+# HTTPie plugin
+
+This plugin adds completion for [HTTPie](https://httpie.org), a command line HTTP
+client, a friendlier cURL replacement.
+
+To use it, add `httpie` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... httpie)
+```
+
+It uses completion from [zsh-completions](https://github.com/zsh-users/zsh-completions).
+
+
+**Maintainer:** [lululau](https://github.com/lululau)