fix links to prompt templates and example selectors

[masafumimori]

Fixes #
links to prompt templates and example selectors on the Prompts page are invalid.

Before submitting

Just a small note that I tried to run make docs_clean and other related commands before PR written here, it gives me an error:

langchain % make docs_clean
Traceback (most recent call last):
  File "/Users/masafumi/Downloads/langchain/.venv/bin/make", line 5, in <module>
    from scripts.proto import main
ModuleNotFoundError: No module named 'scripts'
make: *** [docs_clean] Error 1
# Poetry (version 1.5.1)
# Python 3.9.13

I couldn't figure out how to fix this, so I didn't run those command. But links should work.

Who can review?

Tag maintainers/contributors who might be interested:
@hwchase17

Similar issue #6323

[vercel]

Someone is attempting to deploy a commit to the LangChain Team on Vercel.

A member of the Team first needs to authorize it.

[hwchase17]

thanks!