Doc review follow up

[SMoraisAnsys]

Here are some actions that need to be addressed following #240:

• pyedb documentation must be fixed by adding thumbnails for each examples (DOCS: Missing thumbnails pyedb#790)
• missing/broken thumbnails must be added for "lorentz actuator" (Add thumbnail Lorentz actuator example #238), "HFFS Layout UI modification", and "examples by AEDT application"
  
• key words should be homogenized and avoid capital letters, e.g. "Components" -> "components"
• update the directory names to avoid using numbers, this is no longer required since we defined examples order manually with nbgallery