Function capitalize

capitalize(text: string): string
Capitalizes only the first letter of a string, leaving the rest unchanged.
Parameters
- text: string
  A string to capitalize.
Returns string
The string with its first letter capitalized.
Example
```
capitalize('hello world'); // 'Hello world'
capitalize('HELLO WORLD'); // 'HELLO WORLD'
```
- Defined in text/conventions.ts:13