Add utility classes for opacity (#33781)

* Add responsive utility classes for opacity

- fix for #33483

* remove responsive opacity utils as it has impact on bootstrap.css bundle size

* Update opacity.md

* Update site/content/docs/5.0/utilities/opacity.md

Co-authored-by: Mark Otto <otto@github.com>

* Update site/content/docs/5.0/utilities/opacity.md

Co-authored-by: Mark Otto <otto@github.com>

Co-authored-by: Harish <halodoc@ip-192-168-1-101.ap-southeast-1.compute.internal>
Co-authored-by: XhmikosR <xhmikosr@gmail.com>
Co-authored-by: Mark Otto <otto@github.com>
Co-authored-by: Mark Otto <markd.otto@gmail.com>
Co-authored-by: alpadev <2838324+alpadev@users.noreply.github.com>

scss/_utilities.scss

@@ -24,6 +24,19 @@ $utilities: map-merge(
       )
     ),
     // scss-docs-end utils-float
+    // Opacity utilities
+    // scss-docs-start utils-opacity
+    "opacity": (
+      property: opacity,
+      values: (
+        0: 0,
+        25: .25,
+        50: .5,
+        75: .75,
+        100: 1,
+      )
+    ),
+    // scss-docs-end utils-opacity
     // scss-docs-start utils-overflow
     "overflow": (
       property: overflow,

site/content/docs/5.0/utilities/opacity.md

@@ -0,0 +1,30 @@
+---
+layout: docs
+title: Opacity
+description: Control the opacity of elements.
+group: utilities
+---
+
+The `opacity` property sets the opacity level for an element. The opacity level describes the transparency level, where `1` is not transparent at all, `.5` is 50% visible, and `0` is completely transparent.
+
+Set the `opacity` of an element using `.opacity-{value}` utilities.
+
+<div class="bd-example d-sm-flex">
+  <div class="opacity-100 p-3 m-2 bg-primary text-light fw-bold rounded">100%</div>
+  <div class="opacity-75 p-3 m-2 bg-primary text-light fw-bold rounded">75%</div>
+  <div class="opacity-50 p-3 m-2 bg-primary text-light fw-bold rounded">50%</div>
+  <div class="opacity-25 p-3 m-2 bg-primary text-light fw-bold rounded">25%</div>
+</div>
+
+```html
+<div class="opacity-100">...</div>
+<div class="opacity-75">...</div>
+<div class="opacity-50">...</div>
+<div class="opacity-25">...</div>
+```
+
+### Utilities API
+
+Opacity utilities are declared in our utilities API in `scss/_utilities.scss`. [Learn how to use the utilities API.]({{< docsref "/utilities/api#using-the-api" >}})
+
+{{< scss-docs name="utils-opacity" file="scss/_utilities.scss" >}}

site/data/sidebar.yml

@@ -101,6 +101,7 @@
     - title: Flex
     - title: Float
     - title: Interactions
+    - title: Opacity
     - title: Overflow
     - title: Position
     - title: Shadows