feat: add TAPL Lang file icon

[HetorusNL]

Description

Added TAPL Lang file icon (vscode extension available here).

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[PKief]

Hi @HetorusNL, thanks for creating the new icon. It looks great and aligns with our guidelines. To keep the extension focused on broadly used technologies, we generally avoid shipping icons before the underlying language or project is publicly available and established. Since tapl-lang.com appears to be under construction, we’d prefer to wait and include the icon once the site and initial release are live and once there’s clear broader adoption. This helps ensure we don’t ship icons primarily relevant to early-stage or personal projects to our millions of users. We appreciate your contribution and would be happy to add the icon as soon as those criteria are met.