[Feature] Collapsable left-hand navigation bar

[chipzoller]

I have checked all the prerequisites below and I'm yet experiencing a problem

• Read the README.md
• Have the extended version of Hugo installed
• Used the exampleSite's config.toml as a reference

Describe the feature

The nav bar on the left-hand side is nice, but for some page content (like tables) you could really use the extra screen width. It'd be helpful if users could optionally collapse that side bar on the left and have the content on the page re-flow across that additional space.

Desktop (please complete the following information):

• OS: Mac 10.16.4
• Browser: Firefox 93

[chipzoller]

An example where this would allow for a table to have a better viewing experience on desktop: https://kube-vip.chipzoller.dev/docs/installation/flags/