Update tutorial titles

[guan404ming]

• clarifying that the notebooks are tutorials on NumPy Features and NumPy Applications

• ref: DOC: link in User Guide should be redirected numpy#26768

[rossbar]

My 2 cents: the proposed addition of "Tutorials of" is redundant, as this is already explicitly a tutorials site. I'm -0.5 on changing the titles but will readily acquiesce if other reviewers prefer it!

[melissawm]

I agree with @rossbar, I think this is a bit redundant.

[guan404ming]

Thanks for the reviews! I added "Tutorials of" because directly going to the feature page and application page doesn't clearly indicate it's a tutorial which may cause some confusion. But I'm happy with whatever reviewers prefer!. Thanks again!

[bsipocz]

I also agree with the other maintainers.

However, maybe we can have a different logo flavour, after all it doesn't link back to https://numpy.org but to https://numpy.org/numpy-tutorials/

[guan404ming]

I totally agree that having a different logo will prevent confusion. Thanks a lot for your time, everyone. I'll close this PR now~