💡 [Feature]: Improve SharePoint Framework introduction in walkthrough

[Adam-it]

🎯 Aim of the feature

The aim of the walkthrough is to provide step by step guidance and introduction to SharePoint Framework development and SPFx Toolkit. Unfortunately, the first step which should give guidance regarding SPFx is very small and general. Doesn't include any details and helpful guidance. We should improve this.

we should add information that will explain

• more about SPFx capabilities and features.
• why would someone pick SPFx over a different extensibility model
• what components are possible to be created
• some general info about basic setup

📷 Images (if possible) with expected result

No response

🤔 Additional remarks or comments

We should be updating those parts