Improve renderization of RTL (Right-to-left) languages

<screen> and <programlisting> are always ltr and align to the left
because they usually have pieces of code and commands.

This will lock <screen> and <programlisting> and RTL languages
won't change that.

PR: 247184
Approved by: doceng (bcr)
Differential Revision: https://reviews.freebsd.org/D25238