docs: Fix Your First Smart Contract page issues

[BrianSeong99]

Context

From devrel#126 feedback by @Dominik1999.

Issues to fix

• "Compiles to Miden assembly": Should say compiles to a .masp file
• felt vs Felt not explained: Imports section uses both without explaining the difference
• "Miden component": Should say "Miden Account component" and link to protocol definition
• Storage Key Strategy wording: "Both functions in the counter contract ..." — sentence is unclear
• Trace logs in output: Actual output includes many Trace with id lines not shown in the docs — either document them or suppress them
• Midenscan link: After deploying, link to the account/tx on Midenscan so users can verify