Improve documentation

[pmaroneh]

Description of the modifications

• Need for a "download example" button at the end of each example, as many other PyAnsys libraries do.
• The examples should also show the other scripts, especially the ones contained in .wbjn files, as it is not possible to fully understand the example without it.

Useful links and references

No response

[franknli]

Closing this one given Jorge's change.

[pmaroneh]

@franknli and @jorgepiloto thanks for working on this. However I believe this PR adds only one of my suggestions (having a download button), but what about the other suggestion (showing all the code to have better understanding of the example)?