Update Development Documentation wording

What does this MR do?

The MR is aims to enhance the Documentation of a line in GitLab! Documentation Guidelines in the Testing section.

Screenshots (strongly suggested)

Screenshot__1053_ The changes -(1) Full stop at the end of the sentence. (2) Enhancement in the sentence structure.

Does this MR meet the acceptance criteria?

Yes

Conformity

• 📋 NO Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because _____.
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

No risks are expected with the MR implementation.