fix: SEO-1 (#29)

nodes/string-manipulation/substring/README.md

@@ -0,0 +1,33 @@
+---
+hide_title: true
+hide_table_of_contents: true
+title: Substring
+---
+
+<##head##>
+
+# Substring
+
+This node lets you extract a part of a <span className="ndl-data">string</span> given a start and end character position.
+
+<div className="ndl-image-with-background l">
+
+![](/nodes/string-manipulation/substring/substring_node.png)
+
+</div>
+
+<##head##>
+
+## Inputs
+
+| Data                                     | Description                                                     |
+| ---------------------------------------- | --------------------------------------------------------------- |
+| <span className="ndl-data">String</span> | The source string where the substring should be extracted from. |
+| <span className="ndl-data">Start</span>  | The character index of the start of the substring.              |
+| <span className="ndl-data">End</span>    | The character index of the end of the substring.                |
+
+## Outputs
+
+| Data                                     | Description              |
+| ---------------------------------------- | ------------------------ |
+| <span className="ndl-data">Result</span> | The extracted substring. |