Angular 7 and can't bind to 'routerlink' since it isn't a known property of 'a'
The property routerLink is case sensitive.
change [routerlink] to [routerLink]
[routerLink]="['/vendors']"
For those people who have "routerLink" camel cased correctly and are still getting the same error, you probably have not imported RouterModule inside the module that defines your component.
import {RouterModule} from '@angular/router';
@NgModule({
declarations:[YourComponents],
imports:[RouterModule]
...