[FEATURE] Add support for all_export ENV

[owenstake]

In ubuntu , I use export all_export=http://xxx:xx to proxy http request, but fail to work with wiki-tui. Please add all_proxy support.

[Builditluc]

Hey @owenstake and thank you for the feature request! I'm not familiar with the all_export ENV variable. What does it do (I would guess it sets a proxy for every http request made) and how do you specify the proxy / use the variable?

Currently, I'm rewriting wiki-tui (see #226) and that means the feature would be released with the finished rewrite.

also changing the title for informative purposes