Adds editor configs

[NickSdot]

Adds the same .editorconfig as in doc-en so XML files are aligned in all repos. Also adds .gitattributes so Git normalises text files to LF.

[alfsb]

In translations, trim_trailing_whitespace = true is worth the trouble.

[NickSdot]

In translations, trim_trailing_whitespace = true is worth the trouble.

Can set it true if you want. Here or everywhere?

Edit: why I ask here or everywhere is because I opened this in multiple languages. So I would like to know if your comment "go with trim_trailing_whitespace = true" applies to all repos.

Not sure how your translations workflows look like, but wouldn't that require doc-en to be the same? Also worth to mention: docbook-cs has an auto-fixer for that now.

[alfsb]

In translations, trim_trailing_whitespace = true is worth the trouble.

Can set it true if you want. Here or everywhere?

Not sure how your translations workflows look like, but wouldn't that require doc-en to be the same? Also worth to mention: docbook-cs has an auto-fixer for that now.

Whereas I would want it set as true everywhere, this was considered and rejected in doc-en in the past, as it would cause changes in "unrelated" lines, and diffs is used on translations. So translations can have it set as true, but until doc-en is mass trimmed (and commited with skip-revcheck), this is not a change to be decided without further consideration.

After all, there are about 3260 files with trailnig spaces in doc-en, about 30% of all XML files...

[NickSdot]

Updated.