Wishlist: Add a "hacking" section

Since one of the greatest appeals of the Ubuntu phone is that it's relatively straightforward to modify according to one's wishes, it would be nice if there were a "hacking" section in the guide. (I think it would be unhelpful to assume that people using the help app would be necessarily "linux newbies", even if one thinks that dividing people into "newbies" and "advanced users" is useful.)

The hacking section could consist of something starting along the following lines (please feel free to use as much or as little of this as you see fit and to edit it as mercilessly as you wish, I won't feel offended either way):

File: content/pages/hacking.md

Title: Hacking

*Was the possibility of using a real terminal one of the main reasons you bought an Ubuntu phone? Do you enjoy customising your device? If so, this is the section for you!*
<!---
Add some warning about possibility of breaking system(?)
-->

[TOC]

## Misc

### How do I enable developer mode?
In the "System Settings" app, go to "About this phone" > "Developer mode" and toggle the "Developer Mode" switch. If you haven't set a passcode or passphrase, you will have to now.

## Terminal

### How do I install the terminal? !!QA
First enable developer mode (see above). Then, either search for "Terminal" in the app scope or go [here](https://uappexplorer.com/app/com.ubuntu.terminal) and press install.

### What is the password asked for when one opens the terminal app? !!QA
It's your passcode or passphrase.

### What is the sudo password? !!QA
Again, it's the same as your passcode or passphrase.

### How can one "tab"-complete in the terminal? !!QA
By double-pressing anywhere in the terminal.

### How can one scroll up or down in the terminal (equivalent to Shift-PgUp or Shift-PgDn in xterm or gnome-terminal) !!QA
By two-finger swiping up or down.

### How does one navigate in the shell history (and select recent commands — equivalent to Up and Down arrows in normal bash)? !!QA
By single-finger swiping.

### Are there any editors available out-of-the-box? !!QA
There's nano and vi (really vim.tiny)...

## Links

### What are some good resources for further reading? !!QA
[This e-book](https://www.gitbook.com/book/gurucubano/bq-aquaris-e-4-5-ubuntu-phone/) (also readable online) has many command-line tips for the ubuntu phone, while [this set of blog posts](https://sturmflut.github.io/ubuntu/touch/2015/05/07/hacking-ubuntu-touch-index/) comprehensively deals with more low-level hacking.