Added Note in Workflow Licensing article about using underscore instead of period

[eshanrnh]

📋 Description

A customer experienced validation issues with their Workflow license. According to their feedback:

"I changed the license value from UMBRACO_LICENSES_UMBRACO_WORKFLOW to UMBRACO_LICENSES_Umbraco_Workflow (case sensitive) and instead of using Umbraco.Workflow as the key, I used Umbraco_Workflow (underscore instead of period). The key change is not necessary but changed it for consistency (both ways work).
I'm providing this information in the hopes that the documentation is updated. This issue applies to Umbraco Engage as well. I experienced it when setting it up a couple of days/weeks ago."

Umbraco Engage v13 and v16 already have this Note. So no changes there.

📎 Related Issues (if applicable)

✅ Contributor Checklist

I've followed the Umbraco Documentation Style Guide and can confirm that:

• Code blocks are correctly formatted.
• Sentences are short and clear (preferably under 25 words).
• Passive voice and first-person language (“we”, “I”) are avoided.
• Relevant pages are linked.
• All links work and point to the correct resources.
• Screenshots or diagrams are included if useful.
• Any code examples or instructions have been tested.
• Typos, broken links, and broken images are fixed.

Product & Version (if relevant)

Workflow v10, 13, 14, 15, 16

Deadline (if relevant)

Anytime

📚 Helpful Resources

• 🧾 Umbraco Contribution Guidelines
• ✍️ Umbraco Documentation Style Guide

[sofietoft]

LGTM 💪