Empty tables shouldn't get added as-is to output

[very-doge-wow]

Describe the bug
Not per se a bug, but:
When a table is empty (for example no requirements are present), the empty table simply gets added to the output.

Instead, a simple message like "no requirements found" would suffice.

To Reproduce
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Expected behavior
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Screenshots
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Basic Info (please complete the following information):

• OS:
• stella version:

Additional context
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cc @very-doge-wow

[very-doge-wow]

Fixed with #15