Update link mixin comments

The govuk-link-common mixin is now doing a lot more than just focus states, so update the comments to reflect that.

src/govuk/helpers/_links.scss

@@ -21,7 +21,7 @@
 /// Provides the default unvisited, visited, hover and active states for links.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {
@@ -71,7 +71,7 @@
 /// Provides the error unvisited, visited, hover and active states for links.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {
@@ -118,7 +118,7 @@
 /// Provides the success unvisited, visited, hover and active states for links.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {
@@ -166,7 +166,7 @@
 /// regardless of visited state.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {
@@ -206,7 +206,7 @@
 /// navigation components, such as breadcrumbs or the back link.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {
@@ -240,7 +240,7 @@
 /// Overrides the colour of links to work on a dark background.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {
@@ -282,7 +282,7 @@
 /// that you’ve visited it before is not important.
 ///
 /// If you use this mixin in a component you must also include the
-/// govuk-link-common mixin in order to get the focus state.
+/// govuk-link-common mixin in order to get the correct focus and hover states.
 ///
 /// @example scss
 ///   .govuk-component__link {