Add description in readme for 2 new GCW TR sensors

[stephpenn1]

Two new sensors will be added to GCW TR wetland for the NSF-Radon project. This will be on our loggers and therefor flow through our pipeline, we'll need to:

• add these in the design table when they are installed and
• add a sentence in the GCW readme

For the NSF-Radon project purposes only, two new trees (tree tags will be provided ASAP) will be added to the TR zone in lieu of TR1 and TR6. The addition of the two trees were made after statistical data analyses for gases (Rn, CH4, and CO2) collected from Jul to Oct 2024. We noticed that soil and trees radon fluxes were significantly impacted by soil water content, where drier soil would have more Rn fluxes compared to wet soil. TR1 and TR6 trees were found to be more leaning to an upland soil/site more of a wetland soil/site (that classification for the upland vs wetland pertained only for the NSF-Radon project and has nothing to do with the COMPASS experimental design) . The two new trees that are replacing TR1 and TR6 for the Radon study will be located more towards the marsh/small stream at the TR zone to be more consistent with the rest of the TR trees (TR2, TR3, TR4, and TR5).