[getting_started] syntax issues

[mmcky]

In getting started lecture the following

``!conda install quantecon``

is getting translated to:

`> !conda install quantecon`

which suggests there is an extra block quote in the AST

[mmcky]

fixed by QuantEcon/lecture-python-programming#69

[mmcky]

actually @jstac was the aim for these to be contained in blockquotes?

https://python-programming.quantecon.org/getting_started.html#Installing-Libraries

or would you like them like

https://5f644479d2dd5829b8cb034e--gracious-dubinsky-cc513b.netlify.app/getting_started.html#Installing-Libraries

without the indentation?

May need to reorder the > and the ' in the translator to fix this issue so we end up with

> `!conda install quantecon`

[mmcky]

fixed by executablebooks/sphinx-tomyst#61

[mmcky]

This is now translated to

> `!conda install quantecon`

but this has an issue in markdown-it-py

[mmcky]

This issue can be resolved for quantecon by removing the block-quote context from the source rst files.

QuantEcon/lecture-python-programming#69