Add new feature: Breadcrumb component (#632)

* Add breadcrumb component

* Change breadcrumb component structure

* Remove flex-wrap from breadcrumb component

sass/components/_all.sass

@@ -1,5 +1,6 @@
 @charset "utf-8"
 
+@import "breadcrumb.sass"
 @import "card.sass"
 @import "level.sass"
 @import "media.sass"
@@ -9,4 +10,4 @@
 @import "nav.sass"
 @import "pagination.sass"
 @import "panel.sass"
-@import "tabs.sass"
+@import "tabs.sass"

sass/components/breadcrumb.sass

@@ -0,0 +1,66 @@
+.breadcrumb
+  +block
+  +unselectable
+  align-items: stretch
+  display: flex
+  font-size: $size-normal
+  overflow: hidden
+  overflow-x: auto
+  white-space: nowrap
+  a
+    align-items: center
+    color: $text-light
+    display: flex
+    justify-content: center
+    padding: 0.5em 0.75em
+    &:hover
+      color: $link-hover
+  li
+    align-items: center
+    display: flex
+    &.is-active
+      a
+        color: $text-strong
+        cursor: default
+        pointer-events: none
+    & + li:before
+      color: $text
+      content: '\0002f'
+  ul, ol
+    align-items: center
+    display: flex
+    flex-grow: 1
+    flex-shrink: 0
+    justify-content: flex-start
+  .icon
+    &:first-child
+      margin-right: 0.5em
+    &:last-child
+      margin-left: 0.5em
+  // Alignment
+  &.is-centered
+    ol, ul
+      justify-content: center
+  &.is-right
+    ol, ul
+      justify-content: flex-end
+  // Sizes
+  &.is-small
+    font-size: $size-small
+  &.is-medium
+    font-size: $size-medium
+  &.is-large
+    font-size: $size-large
+  // Styles
+  &.has-arrow-separator
+    li + li:before
+      content: '\02192'
+  &.has-bullet-separator
+    li + li:before
+      content: '\02022'
+  &.has-dot-separator
+    li + li:before
+      content: '\000b7'
+  &.has-succeeds-separator
+    li + li:before
+      content: '\0227B'