minor wording changes

Co-authored-by: Tom Thorogood <[email protected]>
Signed-off-by: Young Shung <[email protected]>

Author: ynshung

topics/covid-19/index.md

@@ -11,4 +11,4 @@ url: https://www.who.int/emergencies/diseases/novel-coronavirus-2019
 wikipedia_url: https://en.wikipedia.org/wiki/Coronavirus_disease_2019
 ---
 
-The coronavirus disease 2019 (COVID-19) is an infectious disease caused by a type of coronavirus known as SARS-CoV-2 that has caused a worldwide pandemic beginning in December 2019. This topic is associated with repositories that contain code focused around research and awareness of the virus.
+The coronavirus disease 2019 (COVID-19) is an infectious disease caused by a type of coronavirus known as SARS-CoV-2 that caused a worldwide pandemic beginning in December 2019. This topic is associated with repositories that contain code focused around research and awareness of the virus.