EN: heading : typo fixed

Author: VitSimon

en/heading.md

@@ -4,7 +4,7 @@
 - Each chapter should start with h1 (1x #) heading which will be the 1st one heading and text on the start of the document.
 
 **HelpViewer** resolves document heading in this order of priority (from most significant):
-- **h1** heading text form chapter text if it is on the start of the document text (skips next points lower here)
+- **h1** heading text from chapter text if it is on the start of the document text (skips next points lower here)
 - TOC item text (📖) when clicked
 - Dictionaries item text (📇, 🔎) when clicked.  
 This serves as a backup heading text. It is also preferred when the user reloads the page.