Fix MCP server URL in README for HTTP switch

[rajeevac]

Purpose

Updated MCP server URL in README to include '/mcp' path. The ealier instructions were missing the /mcp in the URL causing the instructions to not work.

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[ ] New feature to existing sample
[ ] New sample
[ ] Refactoring (no functional changes, no api changes)
[x] Documentation content changes
[ ] Other... Please describe:

README updated?

The top-level readme for this repo contains a link to each sample in the repo. If you're adding a new sample did you update the readme?

[x] Yes
[ ] No
[ ] N/A

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]

• Test the code

 - Launch the MCP server locally using the command line (dotnet run) or docker instructions
 - Connect to the MCP with the documented URL

What to Check

Verify that the following are valid

• Connect is successful

Other Information