Update snippet descriptions

snippets/capitalize.md

@@ -5,15 +5,16 @@ tags: string,intermediate
 
 Capitalizes the first letter of a string.
 
-- Capitalize the first letter of the string and then add it with rest of the string.
+- Use list slicing and `str.upper()` to capitalize the first letter of the string.
+- Use `str.join()` to combine the capitalized first letter with the rest of the characters.
 - Omit the `lower_rest` parameter to keep the rest of the string intact, or set it to `True` to convert to lowercase.
 
 ```py
-def capitalize(s, lower_rest=False):
-  return s[:1].upper() + (s[1:].lower() if lower_rest else s[1:])
+def capitalize(s, lower_rest = False):
+  return ''.join([s[:1].upper(), (s[1:].lower() if lower_rest else s[1:])])
 ```
 
 ```py
 capitalize('fooBar') # 'FooBar'
 capitalize('fooBar', True) # 'Foobar'
-```
+```