Restructure Read operations page

[sarahhaggarty]

Hi @zaleslaw,

Here's a suggested restructure of the Read operations page that also can be used as a template for the Write operations page.

The main changes are:

• to separate topics within the content and place them under their own headers.
• explicitly state the functions to use for specific operations.
• give separate examples for the main use cases of each function.

There are also some stylistic changes like changing the headers from using the gerund (e.g. reading) to the imperative (e.g. read). Let me know if you would like these changes to be dropped.

I also fixed the warning at the bottom of the page.

Please let me know your thoughts.

[zaleslaw]

Could you please summarize the recommendation based on these edits?