Too much indentation inside odoc code blocks inside docstring

[panglesd]

Hello! (And thanks for maintaining this tool!)

Odoc has changed the way it considers indentation in code blocks in ocaml/odoc#1317.

Basically, odoc only "extracts" what's inside this ascii art box::

     {[
     +--------------------------
     |
     |    Content
     |
     +--------------------------
     ]}

In other words, it removes as much indentation as the opening { is indented.

However, by default ocp-indent adds two indentation compared to the opening {: If | is the cursor, hitting tab on:

     {[
|
     ]}

indents to:

     {[
       |
     ]}

instead of

     {[
     |
     ]}

I hope my explanation is not too confusing! And thanks @mbarbin for reporting.