add XElement to data available for XML comments

[dsyme]

No description provided.

[dsyme]

@MangelMaxime Can you check his fixes #710 for you?

[MangelMaxime]

I think this will gives me enough information to format the comments.

There is just one strange thing, which is that the content coming from this fix and the one from the XML file generated when compiling a library is not exactly the same.

From this fix:

<member name="P:Nacara.Core.Types.Partial.Id">
  <summary>
 Unique name of the partial, it is generated from the partial file name.

 <example>
 With the following directory structure,

 <code>
 docs
 ├── index.md
 └── _partials
     ├── dropdown
         └── api.jsx
     └── footer.jsx
 </code>

 There are 2 partials:
 - <c>dropdown/api</c>
 - <c>footer</c></example></summary>
</member>

From XML files:

<member name="P:Nacara.Core.Types.Partial.Id">
 <summary>
 Unique name of the partial, it is generated from the partial file name.

 <example>
 With the following directory structure,

 <code>
 docs
 ├── index.md
 └── _partials
     ├── dropdown
         └── api.jsx
     └── footer.jsx
 </code>

 There are 2 partials:
 - <c>dropdown/api</c>
 - <c>footer</c>

 </example>
 </summary>
</member>

1. <summary> is placed after 2 spaces in one case an 1 in the other.

I think I can adapt my code to adapt to this difference. Hopefully, it doesn't prevent me from generating valid markdown.

Markdown is white-space sensitive, so I am "detection" the unwanted leading white-spaces of the lines and removing them.

2. The end of the XML seems to be collapsed:

 - <c>footer</c></example></summary>

versus

 There are 2 partials:
 - <c>dropdown/api</c>
 - <c>footer</c>

 </example>
 </summary>

This one seems inoffensive.