Better Syntax Highlighting in Long Markdown

Python quickstart gains highlighting

The usage block opens with import, so it is tagged python and GitHub colours it on the repo page.

Input:
```
import yourlib
yourlib.run(config='prod')
```

Output:
```python
import yourlib
yourlib.run(config='prod')
```

Node example tagged javascript

const triggers the JavaScript pattern. A TypeScript example opening the same way is also tagged javascript.

Input:
```
const lib = require('yourlib');
lib.run({ env: 'prod' });
```

Output:
```javascript
const lib = require('yourlib');
lib.run({ env: 'prod' });
```

Shell quickstart stays bare

Install commands are shell, which is not detected. The block is left untagged — add ``` bash ``` by hand for shell highlighting.

Input:
```
npm install yourlib
npm run build
```

Output:
```
npm install yourlib
npm run build
```

package.json snippet tagged json

The block starts with {, matching the JSON rule, so the config example gets coloured.

Input:
```
{
  "scripts": { "build": "tsc" }
}
```

Output:
```json
{
  "scripts": { "build": "tsc" }
}
```

Contributor's hint preserved

A block a contributor tagged ``` toml ``` is left exactly as written, so the tool never overrides a deliberate choice in a shared README.

Input:
```toml
[package]
name = "yourlib"
```

Output:
```toml
[package]
name = "yourlib"
```

Install and run commands are the most common README code, but shell is not in the nine-language set, so they stay untagged. Add ``` bash or sh ``` manually for those blocks.

There is no typescript target. A TS usage block matches the JavaScript pattern and is tagged javascript. Switch it to typescript by hand if your README theme distinguishes them.

Existing hints are never edited. A deliberate ``` text or diff ``` from a PR stays intact through the pass.

Console output and logs match no pattern and are left untagged. Tag them ``` text or console ``` yourself if you want monospace-only styling.

JavaScript is checked before Go and shares const /var . A Go block opening with const ( becomes javascript. Lead with package or func for a correct go tag.

Only backtick fences are scanned. Tilde (~~~) fences and four-space-indented code are skipped — convert or fence them first.

Because tagged blocks are preserved, re-running before each release only touches newly added bare fences. There is no churn on existing tags.

A block starting with { or [ is tagged json. A non-JSON config example that opens with a brace can be mislabelled — review brace-first blocks.

Free tier caps input at 500,000 characters / 1 MB per file. Very large monorepo READMEs beyond that are rejected; use a higher tier (Pro: 5,000,000 / 10 MB) or split the doc with md-splitter.