Implement example: 7GUIs Temperature Converter

[tbreuss]

The implementation must be integrated in this Markdown file:

• https://github.com/tbreuss/mithril-by-examples/blob/main/examples/7gui-temperature-converter.md

And the content should be formatted like here for example:

• https://github.com/tbreuss/mithril-by-examples/blob/main/examples/routing.md

If you have any question, leave a message in the comments.

[narayand16]

@tbreuss Can you assign this issue to me ?

[tbreuss]

@narayand16 I have assigned it to you.

Please note, that the implementation should be placed within the above markdown file. It will then "compiled" and built and in the end referenced to flems via a automatically generated link button. You can see a working example here.

It would be nice when you could code in ES6.

If you have any question on that, let me know.

[narayand16]

@tbreuss Kindly review the updated PR.

[tbreuss]

Fixed with #15