docs: update migration guide url

HHongSeungWoo · HHongSeungWoo · commit 309ceba18077 · 2024-09-20T14:36:31.000+09:00
diff --git a/docs/migration-guide.md b/docs/migration-guide.md
@@ -53,4 +53,4 @@ The biggest change is the handling of `string`s—in 6.x a string could refer to
 
 ---
 
-[See the full CHANGELOG](https://github.com/openapi-ts/openapi-typescript/blob/6.x/packages/openapi-typescript/CHANGELOG.md)
+[See the full CHANGELOG](https://github.com/openapi-ts/openapi-typescript/blob/main/packages/openapi-typescript/CHANGELOG.md)

Original file line number	Diff line number	Diff line change
@@ -53,4 +53,4 @@ The biggest change is the handling of `string`s—in 6.x a string could refer to
`53`	`53`
`54`	`54`	`---`
`55`	`55`
`56`		`-[See the full CHANGELOG](https://github.com/openapi-ts/openapi-typescript/blob/6.x/packages/openapi-typescript/CHANGELOG.md)`
	`56`	`+[See the full CHANGELOG](https://github.com/openapi-ts/openapi-typescript/blob/main/packages/openapi-typescript/CHANGELOG.md)`