fix unescaped open-close (<>) tags (#7756)

Author: julianobrasil

src/lib/icon/icon-registry.ts

@@ -181,7 +181,7 @@ export class MatIconRegistry {
   }
 
   /**
-   * Returns an Observable that produces the icon (as an <svg> DOM element) from the given URL.
+   * Returns an Observable that produces the icon (as an `<svg>` DOM element) from the given URL.
    * The response from the URL may be cached so this will not always cause an HTTP request, but
    * the produced element will always be a new copy of the originally fetched icon. (That is,
    * it will not contain any modifications made to elements previously returned).
@@ -208,7 +208,7 @@ export class MatIconRegistry {
   }
 
   /**
-   * Returns an Observable that produces the icon (as an <svg> DOM element) with the given name
+   * Returns an Observable that produces the icon (as an `<svg>` DOM element) with the given name
    * and namespace. The icon must have been previously registered with addIcon or addIconSet;
    * if not, the Observable will throw an error.
    *