Clarify npm readme

paige/README.md

@@ -2,9 +2,66 @@
 
 ## Update instructions
 
-If you update Bootstrap, rename `node_modules/bootstrap/scss/vendor` to `node_modules/bootstrap/scss/_vendor`.
+If you update Bootstrap:
 
-`node_modules/bootstrap` is modified to apply a
-[critical fix](https://github.com/twbs/bootstrap/commit/f77117141dfe34d8fe984eabddf660e29cb96a57)
-that came after 5.3.0-alpha2.
-Once the fix is included in an NPM package, remove the modification.
+1. Rename `node_modules/bootstrap/scss/vendor` to `node_modules/bootstrap/scss/_vendor`.
+2. Apply this patch:
+
+    ```diff
+    --- a/paige/node_modules/bootstrap/scss/_mixins.scss
+    +++ b/paige/node_modules/bootstrap/scss/_mixins.scss
+    @@ -3,7 +3,7 @@
+     // Used in conjunction with global variables to enable certain theme features.
+
+     // Vendor
+    -@import "vendor/rfs";
+    +@import "_vendor/rfs";
+
+     // Deprecate
+     @import "mixins/deprecate";
+    diff --git a/paige/node_modules/bootstrap/scss/vendor/_rfs.scss b/paige/node_modules/bootstrap/scss/_vendor/_rfs.scss
+    similarity index 100%
+    rename from paige/node_modules/bootstrap/scss/vendor/_rfs.scss
+    rename to paige/node_modules/bootstrap/scss/_vendor/_rfs.scss
+    diff --git a/paige/node_modules/bootstrap/scss/bootstrap-grid.scss b/paige/node_modules/bootstrap/scss/bootstrap-grid.scss
+    index 52bd577..c82f6bc 100644
+    --- a/paige/node_modules/bootstrap/scss/bootstrap-grid.scss
+    +++ b/paige/node_modules/bootstrap/scss/bootstrap-grid.scss
+    @@ -13,7 +13,7 @@ $include-column-box-sizing: true !default;
+     @import "mixins/grid";
+     @import "mixins/utilities";
+
+    -@import "vendor/rfs";
+    +@import "_vendor/rfs";
+
+     @import "containers";
+     @import "grid";
+    ```
+
+3. Apply this patch if needed:
+
+    ```diff
+    diff --git a/paige/node_modules/bootstrap/scss/_carousel.scss b/paige/node_modules/bootstrap/scss/_carousel.scss
+    index b17d27f493b..0ac8f8714fb 100644
+    --- a/paige/node_modules/bootstrap/scss/_carousel.scss
+    +++ b/paige/node_modules/bootstrap/scss/_carousel.scss
+    @@ -230,9 +230,15 @@
+
+     @if $enable-dark-mode {
+       @include color-mode(dark) {
+    -    .carousel,
+    -    &.carousel {
+    -      @include carousel-dark();
+    +    @if $color-mode-type == "media-query" {
+    +      .carousel {
+    +        @include carousel-dark();
+    +      }
+    +    } @else {
+    +      .carousel,
+    +      &.carousel {
+    +        @include carousel-dark();
+    +      }
+         }
+       }
+     }
+    ```