Add valuable reference content from PR #10

Cherry-picked the genuinely unique content from PR #10 and integrated
into existing skills:

seo-audit/references:
- ai-writing-detection.md: AI writing patterns to avoid (em dashes,
  overused phrases, filler words)
- aeo-geo-patterns.md: Answer Engine & Generative Engine Optimization
  content patterns

copy-editing/references:
- plain-english-alternatives.md: Complex to simple word replacements

copywriting/references:
- natural-transitions.md: Transitional phrases for better content flow

Updated SKILL.md files to link to new references.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/copywriting/references/natural-transitions.md

@@ -0,0 +1,252 @@
+# Natural Transitions
+
+Transitional phrases to guide readers through your content. Good signposting improves readability, user engagement, and helps search engines understand content structure.
+
+Adapted from: University of Manchester Academic Phrasebank (2023), Plain English Campaign, web content best practices
+
+---
+
+## Previewing Content Structure
+
+Use to orient readers and set expectations:
+
+- Here's what we'll cover...
+- This guide walks you through...
+- Below, you'll find...
+- We'll start with X, then move to Y...
+- First, let's look at...
+- Let's break this down step by step.
+- The sections below explain...
+
+---
+
+## Introducing a New Topic
+
+- When it comes to X,...
+- Regarding X,...
+- Speaking of X,...
+- Now let's talk about X.
+- Another key factor is...
+- X is worth exploring because...
+
+---
+
+## Referring Back
+
+Use to connect ideas and reinforce key points:
+
+- As mentioned earlier,...
+- As we covered above,...
+- Remember when we discussed X?
+- Building on that point,...
+- Going back to X,...
+- Earlier, we explained that...
+
+---
+
+## Moving Between Sections
+
+- Now let's look at...
+- Next up:...
+- Moving on to...
+- With that covered, let's turn to...
+- Now that you understand X, here's Y.
+- That brings us to...
+
+---
+
+## Indicating Addition
+
+- Also,...
+- Plus,...
+- On top of that,...
+- What's more,...
+- Another benefit is...
+- Beyond that,...
+- In addition,...
+- There's also...
+
+**Note:** Use "moreover" and "furthermore" sparingly. They can sound AI-generated when overused.
+
+---
+
+## Indicating Contrast
+
+- However,...
+- But,...
+- That said,...
+- On the flip side,...
+- In contrast,...
+- Unlike X, Y...
+- While X is true, Y...
+- Despite this,...
+
+---
+
+## Indicating Similarity
+
+- Similarly,...
+- Likewise,...
+- In the same way,...
+- Just like X, Y also...
+- This mirrors...
+- The same applies to...
+
+---
+
+## Indicating Cause and Effect
+
+- So,...
+- This means...
+- As a result,...
+- That's why...
+- Because of this,...
+- This leads to...
+- The outcome?...
+- Here's what happens:...
+
+---
+
+## Giving Examples
+
+- For example,...
+- For instance,...
+- Here's an example:...
+- Take X, for instance.
+- Consider this:...
+- A good example is...
+- To illustrate,...
+- Like when...
+- Say you want to...
+
+---
+
+## Emphasising Key Points
+
+- Here's the key takeaway:...
+- The important thing is...
+- What matters most is...
+- Don't miss this:...
+- Pay attention to...
+- This is critical:...
+- The bottom line?...
+
+---
+
+## Providing Evidence
+
+Use when citing sources, data, or expert opinions:
+
+### Neutral attribution
+- According to [Source],...
+- [Source] reports that...
+- Research shows that...
+- Data from [Source] indicates...
+- A study by [Source] found...
+
+### Expert quotes
+- As [Expert] puts it,...
+- [Expert] explains,...
+- In the words of [Expert],...
+- [Expert] notes that...
+
+### Supporting claims
+- This is backed by...
+- Evidence suggests...
+- The numbers confirm...
+- This aligns with findings from...
+
+---
+
+## Summarising Sections
+
+- To recap,...
+- Here's the short version:...
+- In short,...
+- The takeaway?...
+- So what does this mean?...
+- Let's pull this together:...
+- Quick summary:...
+
+---
+
+## Concluding Content
+
+- Wrapping up,...
+- The bottom line is...
+- Here's what to do next:...
+- To sum up,...
+- Final thoughts:...
+- Ready to get started?...
+- Now it's your turn.
+
+**Note:** Avoid "In conclusion" at the start of a paragraph. It's overused and signals AI writing.
+
+---
+
+## Question-Based Transitions
+
+Useful for conversational tone and featured snippet optimization:
+
+- So what does this mean for you?
+- But why does this matter?
+- How do you actually do this?
+- What's the catch?
+- Sound complicated? It's not.
+- Wondering where to start?
+- Still not sure? Here's the breakdown.
+
+---
+
+## List Introductions
+
+For numbered lists and step-by-step content:
+
+- Here's how to do it:
+- Follow these steps:
+- The process is straightforward:
+- Here's what you need to know:
+- Key things to consider:
+- The main factors are:
+
+---
+
+## Hedging Language
+
+For claims that need qualification or aren't absolute:
+
+- may, might, could
+- tends to, generally
+- often, usually, typically
+- in most cases
+- it appears that
+- evidence suggests
+- this can help
+- many experts believe
+
+---
+
+## Best Practice Guidelines
+
+1. **Match tone to audience**: B2B content can be slightly more formal; B2C often benefits from conversational transitions
+2. **Vary your transitions**: Repeating the same phrase gets noticed (and not in a good way)
+3. **Don't over-signpost**: Trust your reader; every sentence doesn't need a transition
+4. **Use for scannability**: Transitions at paragraph starts help skimmers navigate
+5. **Keep it natural**: Read aloud; if it sounds forced, simplify
+6. **Front-load key info**: Put the important word or phrase early in the transition
+
+---
+
+## Transitions to Avoid (AI Tells)
+
+These phrases are overused in AI-generated content:
+
+- "That being said,..."
+- "It's worth noting that..."
+- "At its core,..."
+- "In today's digital landscape,..."
+- "When it comes to the realm of..."
+- "This begs the question..."
+- "Let's delve into..."
+
+See the seo-audit skill's `references/ai-writing-detection.md` for a complete list of AI writing tells.