docs: update string function expression example docs

Author: ahochsteger

docs/docs/examples/advanced/stringFnExpressions.mdx

@@ -11,14 +11,14 @@ import { info } from "../../../../src/examples/advanced/stringFnExpressions.ts"
 This example shows how to use string functions within expressions.
 
 The following string functions are supported:
-- replace(searchRegexp, replacement)
-- replaceAll(searchRegexp, replacement)
-- slice(start, end)
-- substring(start, end)
-- trimStart()
-- trimEnd()
-- trim()
-- toUpperCase()
-- toLowerCase()
+- `replace(searchRegexp, replacement)`: Replaces the first occurrence of a pattern matching the regular expression with a replacement string. See [`String.prototype.replace()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace).
+- `replaceAll(searchRegexp, replacement)`: Replaces all occurrences of a pattern matching the regular expression with a replacement string. See [`String.prototype.replaceAll()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replaceAll).
+- `slice(start, end)`: Extracts a section of a string and returns it as a new string, without modifying the original string. See [`String.prototype.slice()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice).
+- `substring(start, end)`: Returns the part of the string between the start and end indexes, or to the end of the string. See [`String.prototype.substring()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substring).
+- `trimStart()`: Removes whitespace from the beginning of a string. See [`String.prototype.trimStart()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trimStart).
+- `trimEnd()`: Removes whitespace from the end of a string. See [`String.prototype.trimEnd()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trimEnd).
+- `trim()`: Removes whitespace from both ends of a string. See [`String.prototype.trim()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trim).
+- `toUpperCase()`: Converts a string to uppercase letters. See [`String.prototype.toUpperCase()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase).
+- `toLowerCase()`: Converts a string to lowercase letters. See [`String.prototype.toLowerCase()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toLowerCase).
 
 <RenderExample info={info} config={config} script={script} />