feat: add Soundtrap activity

[STAELH81]

Description

Adds a new activity for Soundtrap Studio.

The activity shows:

• Current project name
• Play, pause and recording status
• Current position and project duration
• BPM, key and time signature
• English and French language options

The activity is only intended to display when using the Soundtrap Studio.

Acknowledgements

• I read the Activity Guidelines
• I linted the code by running npm run lint
• The PR title follows the repo's commit conventions

Screenshots

Proof showing the activity working

Playing

Paused

Recording

Settings

[dimerp]

🖼️ Activity asset preview

Asset inspection complete. No pixels were harmed in the making of this comment. 🤖

Soundtrap (websites/S/Soundtrap) — creation

Preview	Source	URL
	logo	https://i.imgur.com/EuIrH5x.png
	thumbnail	https://i.imgur.com/puVy77T.jpeg
	code (presence.ts)	https://raw.githubusercontent.com/STAELH81/premid-assets/main/logo.png

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