Update foundry cast verion:

[machuwey]

Updated 2.8 & 2.8.1 section.

• Updated documentation to work with latest version of scarb and starknet:

# scarb --version
scarb 2.4.3
cairo: 2.3.0
sierra: 1.4.0

# snforge --version
snforge 0.14.0

# sncast --version
sncast 0.14.0

• Updated code snippets in 2.8 and uploaded a repo, so people can jump into the section with more ease.
• Updated deployment script to grab the class hash correctly at the deployment script at 2.8.1
• Reformatted and added lines to docs for more clarity.

Test:
Went though the whole process, with the dependencies listed above, and ensured it is all working.

Closes #291
@gianalarcon