fix(docs): known issue due to pulldown-cmark-to-cmark is solved

ref:
- #40

README.md

@@ -23,51 +23,5 @@ fuga`;
 
 We use [pulldown-cmark](https://crates.io/crates/pulldown-cmark)(rust libary) to parse.
 
-We use [pulldown-cmark-to-cmark](https://crates.io/crates/pulldown-cmark-to-cmark)(rust libary) to replace.
-
-## Known Issue
-
-Because of [pulldown-cmark-to-cmark](https://crates.io/crates/pulldown-cmark-to-cmark) limitation, all code block will be replaced like below:
-
-`before`:
-
-    ```typescript
-    console.log("arikitari na sekai");
-    ```
-
-`after`:
-
-    ````typescript
-    console.log("arikitari na sekai");
-    ````
-
-Almost all cases, that is no problem because HTML converted result will be equal.
-
-However, in some cases, the replaced result will be broken.
-
-`before`:
-
-``````markdown
-`````markdown
-````markdown
-```typescript
-console.log("arikitari na sekai");
-```
-````
-`````
-``````
-
-`after`:
-
-    ````markdown
-    ````markdown
-    ```typescript
-    console.log("arikitari na sekai");
-    ```
-    ````
-    ````
-
-
-
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