formatting

README.md

@@ -5,6 +5,9 @@ A collection of open instruments to help the pandemic recovery effort, supplemen
 ## explorations
 
 [pulse oximetry](pulseox.md)
+
 [infrared temperature measurement](irtemp.md)
+
 [airflow validation](airflowvalidation.md)
+
 [respiration sensing](respirationsensing.md)