fix typo on first page (intent => intend)

Author: dunxen

src/README.md

@@ -45,7 +45,7 @@ What's out of scope for this book:
 - Covering Rustic, low level details. We won't be talking about linker scripts, the boot process or
   how to glue those two into a minimally working Rust program.
 
-Also I don't intent to port this material to other development boards; this book will make exclusive
+Also I don't intend to port this material to other development boards; this book will make exclusive
 use of the STM32F3DISCOVERY development board.
 
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