Clarify default.extend-words

[justanotheranonymoususer]

The docs say:

When the correction is blank, the word is never valid. When the correction is the key, the word is always valid.

But it doesn't say what it means for the correction to be different. There's an example with no explanation.
When I say tais = "taits", what does that mean? That tais is treated as taits?

So for example, if "bhvr" is my abbr for "behavior", I can set bhvr = "behavior", is that right? When can it be more useful than just setting bhvr = "bhvr"?

typos/docs/reference.md

Lines 200 to 212 in 626c4be

	#### `default.extend-words`
	- Type: table of strings
	Corrections for [words](./design.md#identifiers-and-words). When the correction is blank, the word is never valid. When the correction is the key, the word is always valid.
	Example:
	```toml
	[default.extend-words]
	## Project-specific acronym
	taits = "taits"
	tais = "taits"
	```

[epage]

9f99fb8 clarifies that the table maps typos to corrections.

So in the example, taits is always valid while tais is corrected to taits.

[justanotheranonymoususer]

Thanks, maybe you could add that to the docs:

Example:

[default.extend-words]
## Project-specific acronym
## `taits` is always valid while `tais` is corrected to `taits`
taits = "taits"
tais = "taits"