Fixed Session Cookie header

What does this MR do?

This MR fixes the wiki text header for the Session Cookie section

Are there points in the code the reviewer needs to double check?

It is markdown so probably not. Two very simple changes - first is replacing a dot with a space (was causing invalid markdown, not rendered as a header) and capitalized the word Cookie to match the other header formatting.

Why was this MR needed?

Fix the wiki documentation.

Screenshots (if relevant)

None.

Does this MR meet the acceptance criteria?

I can't imagine it wouldn't.

• CHANGELOG entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

I didn't think this warranted an issue as it is just some simple wiki markdown formatting with little to no consequence.