Fix some typos and wording in docs for installation
Fix some typos and wording in docs for installation

ismailsimsek/schemaspy,wkasa/schemaspy,Riggs333/schemaspy,Riggs333/schemaspy,Riggs333/schemaspy,ismailsimsek/schemaspy,wkasa/schemaspy,ismailsimsek/schemaspy,wkasa/schemaspy,Riggs333/schemaspy,wkasa/schemaspy,ismailsimsek/schemaspy