Merge pull request #136 from ldez/feature/missing-doc

doc: adds missing documentation.

docs/strings.md

@@ -30,6 +30,14 @@ Trim just the suffix from a string:
 trimSuffix "-" "hello-"
 ```
 
+## trimPrefix
+
+Trim just the suffix from a string:
+
+```
+trimPrefix "-" "-hello"
+```
+
 The above returns `hello`
 
 ## upper
@@ -324,6 +332,24 @@ kebabcase "FirstName"
 
 This above will produce `first-name`.
 
+## swapcase
+
+Swap the case of a string using a word based algorithm.
+
+Conversion algorithm:
+
+- Upper case character converts to Lower case 
+- Title case character converts to Lower case 
+- Lower case character after Whitespace or at start converts to Title case 
+- Other Lower case character converts to Upper case 
+- Whitespace is defined by unicode.IsSpace(char).
+
+```
+swapcase "This Is A.Test"
+```
+
+This above will produce `tHIS iS a.tEST`.
+
 ## shuffle
 
 Shuffle a string.