Update rethemendex.sh

This commit updates rethemendex.sh, so that any CSS files in "_sc" folder are excluded from being included to alphabetic sorting which causes cascading mess, ensuring `_customization.pcss` is imported at the end of the file.

This also removes warning message from README.md as this update takes care of importing our CSS files.

res/css/_sc/README.md

@@ -24,4 +24,4 @@ Even if the properties are styled with `!important` by the upstream to cover reg
 
 The way in which the upstream project generates concatenated CSS files has been very stable (essentially same since at least 2018. See: https://github.com/matrix-org/matrix-react-sdk/commits/develop/res/css/rethemendex.sh), so we should be able to depend on the current way how it works for a reasonable time.
 
-**Warning: running `rethemendex` breaks cascading!** Manual editing is required for now.
+**Please do not forget to update `_customization.pcss`** if you have added other CSS files for customization. Please mind where to import the files as it affects how styles cascade. Never import them alphabetically.

res/css/_sc/_customization.pcss

@@ -15,5 +15,7 @@ limitations under the License.
 */
 
 /* TODO: replace @import with @mixin once multiple CSS files are created for customization in order to keep styling modular */
+/* Please mind where to import CSS files as it affects how styles cascade. */
+
 @import "./views/rooms/_EventTile.pcss";
 @import "./views/rooms/_IRClayout.pcss";

res/css/rethemendex.sh

@@ -8,8 +8,17 @@ cd `dirname $0`
     # we used to have exclude /themes from the find at this point.
     # as themes are no longer a spurious subdirectory of css/, we don't
     # need it any more.
-    find . -iname _\*.pcss | fgrep -v _components.pcss | LC_ALL=C sort |
+    #
+    # Exclude "_sc" folder dedicated for our custom CSS files from being included
+    # to alphabetic sorting which causes cascading mess. Please note that CSS files
+    # inside the folder are imported at the end.
+    find . -iname _\*.pcss -not -path "./_sc/*" | fgrep -v _components.pcss | LC_ALL=C sort |
         while read i; do
             echo "@import \"$i\";"
         done
+
+        # Import the CSS file dedicated for customization to let our declarations
+        # inside it override the styles specified by the upstream project.
+        echo "\n/* Customization for SchildiChat */";
+        echo "@import \"./_sc/_customization.pcss\";";
 } > _components.pcss