Update introduction.md

Author: Cool-Katt

exercises/practice/error-handling/.docs/introduction.md

@@ -13,18 +13,14 @@ You will learn how to:
 Implement the processString function using a `try…catch` block.
 
 Inside the `try` block:
-
 - If the input is not a string, throw a `TypeError`.
-
 - If the input is an empty string, return `null`.
-
 - If input length is greater than 100, or less than 10, throw a `RangeError`
-
 - If input contains a mix of letters and numbers, throw a `SyntaxError`.
-
 - Otherwise, return the input in `uppercase`.
 
-Don't forget to attach appropriate error messages then you throw! An informative and well structured error message can save you hours of debugging.
+*Don't forget to attach appropriate error messages then you throw! An informative and well structured error message can save you hours of debugging.*
+
 Inside the `catch` block:
 - log the error's message using `console.log`
-- `throw` the `error` so it can be tested for its type.
+- `throw` the `error` so it can be tested for its type.