changing some names from Vaccine to Drug

docs/SymptomsCausedByDrugs/js/PrrByVaccineProvider.js

@@ -1,10 +1,10 @@
 class PrrByVaccineProvider {
 
     static getPrrByVaccine(symptom) {
-        return fetch(`./data/ProportionalReportingRatios/symptoms/${symptom}`).then(response => response.json());
+        return fetch(`./data/ProportionalReportingRatios/symptoms/${symptom}.json`).then(response => response.json());
     }
 
     static getPrrBySymptom(vaccine) {
-        return fetch(`./data/ProportionalReportingRatios/vaccines/${vaccine}`).then(response => response.json());
+        return fetch(`./data/ProportionalReportingRatios/vaccines/${vaccine}.json`).then(response => response.json());
     }
 }