Excessive paragraph indentation throughout [concepts.lang]

[W-E-Brown]

Looking at N4861, all paragraphs following a code block defining a concept seem excessively indented throughout subclause [concepts.lang].

The 1st example of this seems to be [concept.same]/1.

[concept.commonref]/2 and /3 demonstrate that multiple paragraphs are affected, but only after a code block, as /1, before the code block, seems correctly indented.

[CaseyCarter]

I obviously can't tell anyone what they think does or doesn't look good, but this is at least expected.

This is the "normal" indentation that results from using the itemdescr environment for the specification of the declaration in an accompanying itemdecl environment. itemdescrs are indented substantially relative to plain text paragraphs. The end of [vector.bool] shows similar indentation:

There are "normal" paragraphs in the first section (which I've delimited in red) with very little indent, and then alternative itemdecls (green) with similar indent and itemdescrs (blue) with their larger indent.

[JohelEGP]

I think this is related to #2528 and #2648, in that concepts don't have their own descriptive elements like (template) functions do.

[jensmaurer]

To clarify, this is not a LaTeX bug/accident, but directly caused by the LaTeX constructs used in the descriptions. But we don't seem to be consistent: [concept.swappable] p4 is not indented, surprisingly.
Plus the extra indent does look a bit odd, absent the special library description introducers.

[tkoeppe]

Editorial meeting decision: We should remove the itemdescr throught clause [concept]: most corresponding itemdecls are the only ones in their subclause, so there's little danger of losing the clarity of where the text belongs, and the current visual appearance looks unmotivated and confusing.