docs: update

README.md

@@ -7,4 +7,47 @@ A collection of pure POSIX `sh` alternatives to external processes
 
 <!-- vim-markdown-toc GFM -->
 
+* [STRINGS](#strings)
+    * [Strip pattern from start of string](#strip-pattern-from-start-of-string)
+    * [Strip pattern from end of string](#strip-pattern-from-end-of-string)
+
 <!-- vim-markdown-toc -->
+
+
+# STRINGS
+
+## Strip pattern from start of string
+
+**Example Function:**
+
+```sh
+lstrip() {
+    # Usage: lstrip "string" "pattern"
+    printf '%s\n' "${1##$2}"
+}
+```
+
+**Example Usage:**
+
+```shell
+$ lstrip "The Quick Brown Fox" "The "
+Quick Brown Fox
+```
+
+## Strip pattern from end of string
+
+**Example Function:**
+
+```sh
+rstrip() {
+    # Usage: rstrip "string" "pattern"
+    printf '%s\n' "${1%%$2}"
+}
+```
+
+**Example Usage:**
+
+```shell
+$ rstrip "The Quick Brown Fox" " Fox"
+The Quick Brown
+```