Docs: Spelling error

[FlyingStitchman]

therms -> terms

To make it easier to merge your pull request, you should divide your PR into smaller and easier-to-verify units.

Please do not make a pull requests with a lot of modifications which are difficult to check. If I merge pull requests blindly then there is a high risk this software will become a mess quickly for everybody.

[Kreijstal]

That's nice but for the moment it seems this is unmantained

[Kreijstal]

if you do a pr here i'll accept it https://github.com/Kreijstal/PySpice/tree/patch-2