docs: full copy-edit of enhanced depends page

[agilgur5]

Follow-up to #13087 (review) and my other full page copy-edits of docs
Fixes #8693 (comment)
Addresses the first question of #10363 as well

Motivation

Heavily simplify the page, elaborate on some details, and use consistent, up-to-date style

Modifications

larger style changes:

• heavily simplify several sentences and paragraphs, per k8s style guide
  • remove unnecessary "Introduction" section -- just introduce it
    • describe how depends improves on dependencies, instead of explaining the history and limitations
      • same description, but substantially more concise and no longer dated
  • remove some redundant short descriptions like "or failed" that are described better and in more detail almost immediately after
  • simplify the task result table by combining "Description" and "Meaning"
    • previously "Description" was redundant, repeating the result

• remove dated statements like "new" etc, per k8s style guide
  • Also, "Previous to version 2.8" has a grammatical error, seems incorrect (directly above says v2.9), and is not consistent with our existing versioning usage (c.f. docs: consistently use "> v{version} and after" #12581), which is the > v2.9 and after that already exists above

• "the user" -> "you", per k8s style guide
  • similarly, use active voice, per k8s style guide
  • and use a more consistent tense as well

• consistently use "results"; do not use "status" sometimes to mean the same thing -- inconsistency is confusing

  • similarly, use the word "unspecified" instead of "omitted" when referring to a task with no result specified -- .Omitted is an existing term here already
    • elaborate why this exists; it's not just for convenience, it's for compat with dependencies

• elaborate why continueOn is not available either; it can be substituted by .Failed in depends

smaller style modifications:

• remove modifiers like "easy", per k8s style guide
  • similarly remove modifiers like "complex" and "full"; those modifiers felt misleading given that the boolean logic only has 3 operators
• remove Latin abbreviations like "etc", per k8s style guide
• prefer 1 sentence per line of markdown, per style guide

Verification

1. make docs passes
2. See rendered markdown