Update CLIP Text Encode node documentation

[polydecay]

This PR adds documentation for wildcards and comments to the CLIP Text Encode node as described in the main ComfyUI README here.

NOTE: I made two commits for this: the first is a minimal commit that adds wildcards and comments to the existing documentation. The second commit is a more opinionated refactor of the CLIP Text Encode documentation. Please let me know if you don't like the larger refactor, and I'll revert it to the minimal commit instead.

---

While adding wildcards and comments, I noticed the overall documentation could be improved, so I reviewed all of it. The refactor brings several improvements beyond adding the missing features; here are some of the main ones:

• Reduced the overreliance on bullet points, which previously made the text read awkwardly.
• Reduced overall "fluff" words (e.g., "like") to make the text more concise and professional.
• Clarified that weights can be reduced by using values below 1.0.
• Added instructions for including literal () in prompts.
• Clarified that "prompt" corresponds to "description" in the input section for beginners unfamiliar with the terminology.
• Removed general tips for writing prompts because best practices depend on the model (for example, some models work better with tag-based prompting).
• Moved the "important" notes about embeddings into the embedding section to make them easier to find when skimming.
• The EasyNegative embedding is supposed to be used in the negative prompt, so I made the surrounding words in the example negative as well.

[comfyui-wiki]

Thanks for contributing.