[#736] Document usage of $TERM and $TERMINFO env vars

Description

We found that the issue is somewhat alleviated by setting the $TERMINFO and $TERM variables to point to the terminfo database and the terminal type respectively. So we have to update the docs to reflect this advice.

Related issue(s)

Resolves #736 (closed)

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• Tests (see short guidelines)

  • If I added new functionality, I added tests covering it.
  • If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.

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