publish libraries to avoid users to have to download them one by one

lib/SparkFun_BME280/library.properties

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+name=SparkFun BME280
+version=1.2.0
+author=Marshall Taylor
+maintainer=SparkFun Electronics <sparkfun.com>
+sentence=A library to drive the Bosch BME280 Altimeter and Pressure sensor
+paragraph=See code for comments.
+category=Sensors
+url=https://github.com/sparkfun/SparkFun_BME280_Arduino_Library
+architectures=*