DOC: fix incomplete parameter description and examples in as_strided - #33103

PR summary

Small fixes to the numpy.lib.stride_tricks.as_strided docstring:

• The description of x was an incomplete sentence ("Array to create a new."); it now reads "Array to create a new view of."
• check_bounds is now marked as optional, with its default (None, no check) documented.
• The examples hard-coded strides=(8,) and strides=(400,), which assume an 8-byte integer dtype and contradict the Notes, which advise basing new strides on x.strides. They now use x.strides and 50 * a.strides[0].
• In the examples, separate statements were written as ... continuation lines. They now use >>> prompts, as in the rest of the docs.
• Minor wording fixes: "See also" → "See Also", "userfriendly" → "user-friendly", "self overlapping" → "self-overlapping", and "as_strided will raises an error".

The last example now shows c (array([ 0, 50])) instead of c[0], c[1], so the output does not depend on how NumPy scalars are printed.

Documentation-only change; no behavior changes.

First time contributor introduction

This is my third PR, after #33092 and #33094. I use Python for work, for my studies and for personal projects.

AI Disclosure

I used Claude (Anthropic) to review the as_strided docstring, draft these fixes and draft this PR description. I reviewed every change and ran the updated examples with doctest, and I take responsibility for the change. I'll handle all review discussion myself.