Update README.md

Remove outdated mention of one line installer

Author: helgibbons

README.md

@@ -9,8 +9,6 @@ Designed for environmental monitoring, Enviro+ lets you measure air quality (pol
 
 # Installing
 
-You are best using the "One-line" install method if you want all of the UART serial configuration for the PMS5003 particulate matter sensor to run automatically.
-
 **Note** The code in this repository supports both the Enviro+ and Enviro Mini boards. _The Enviro Mini board does not have the Gas sensor or the breakout for the PM sensor._
 
 ![Enviro Plus pHAT](https://raw.githubusercontent.com/pimoroni/enviroplus-python/main/Enviro-Plus-pHAT.jpg)