Fix README link to allwpilib license, which is now in Markdown format (#1773)

Author: PeterJohnson

README.md

@@ -11,7 +11,7 @@ The website is available under the following domains, it is preferred to use the
 - https://frc-docs.readthedocs.io/en/latest/
 
 # WPILib Mission
-The WPILib Mission is to enable FIRST Robotics teams to focus on writing game-specific software rather than focusing on hardware details - "raise the floor, don't lower the ceiling". We work to enable teams with limited programming knowledge and/or mentor experience to be as successful as possible, while not hampering the abilities of teams with more advanced programming capabilities. We support Kit of Parts control system components directly in the library. We also strive to keep parity between major features of each language (Java, C++, and NI's LabVIEW), so that teams aren't at a disadvantage for choosing a specific programming language. WPILib is an open source project, licensed under the BSD 3-clause license. You can find a copy of the license [here](https://github.com/wpilibsuite/allwpilib/blob/main/LICENSE.txt).
+The WPILib Mission is to enable FIRST Robotics teams to focus on writing game-specific software rather than focusing on hardware details - "raise the floor, don't lower the ceiling". We work to enable teams with limited programming knowledge and/or mentor experience to be as successful as possible, while not hampering the abilities of teams with more advanced programming capabilities. We support Kit of Parts control system components directly in the library. We also strive to keep parity between major features of each language (Java, C++, and NI's LabVIEW), so that teams aren't at a disadvantage for choosing a specific programming language. WPILib is an open source project, licensed under the BSD 3-clause license. You can find a copy of the license [here](https://github.com/wpilibsuite/allwpilib/blob/main/LICENSE.md).
 
 # Contributing to frc-docs