Modify current examples with section titles

### Description of the modifications

Add more sections like Introduction, Materials etc as same as from the Mechanical help

### Useful links and references

_No response_

Start by reviewing the current examples and comparing their structure with the Mechanical help referenced in the issue. Identify which examples need section titles such as Introduction and Materials; done means the relevant examples consistently include the requested sections.

Written by the indexing model from the issue text.