Use proper conjunction in example comments (bootstrap-vue#6778)

Co-authored-by: Illya Klymov <xanf@xanf.me>

Author: Sensational-Code

docs/markdown/intro/README.md

@@ -157,7 +157,7 @@ the 2 `@import`'s at the end:
 $body-bg: #000;
 $body-color: #111;
 
-// Then import Bootstrap an BootstrapVue SCSS files (order is important)
+// Then import Bootstrap and BootstrapVue SCSS files (order is important)
 @import 'node_modules/bootstrap/scss/bootstrap.scss';
 @import 'node_modules/bootstrap-vue/src/index.scss';
 ```