Add option for HTML handling when using DeepL

[ClementZezukaLivestorm]

Hey 👋

According to the documentation, DeepL is capable of HTML handling.

However, the plugin seems not configured to handle a such case, which is too bad knowing that a multiline-line string field can be configured as an HTML editor.

For instance, the following input:

<p>Without <strong>articles</strong>, it would be difficult to determine which <strong>nouns</strong> are being referred to in a <strong>sentence</strong>.</p>
<p>Moreover, articles help us to <strong>express</strong> the meaning of a sentence more <strong>clearly</strong>.</p>

Is not correctly translated In French, here is the output:

<p>Sans <strong>articles</strong>il serait difficile de déterminer quel <strong>noms</strong> sont mentionnés dans un <strong>condamnation</strong>.</p>
<p>En outre, les articles nous aident à <strong>express</strong> le sens d'une phrase plus <strong>clairement</strong>.</p>

In order to compare, here is the expected output when DeepL is correctly configured:

<p>Sans <strong>article</strong>, il serait difficile de déterminer les <strong>noms</strong> auxquels il est fait référence dans une phrase.</p>
<p>En outre, les articles nous aident à <strong>exprimer</strong> plus <strong>clairement</strong> le sens d'une phrase.</p>

Do you plan to implement this feature in a near future?

Thanks a lot!

[Siilwyn]

Good addition, can be added to the DeepL options so open for a PR.