[orx-palette] Add ColorBrewer2, demos, update README (#363)

orx-palette/build.gradle.kts

@@ -1,10 +1,28 @@
 plugins {
-    org.openrndr.extra.convention.`kotlin-jvm`
+    org.openrndr.extra.convention.`kotlin-multiplatform`
 }
 
-dependencies {
-    implementation(libs.gson)
-    implementation(project(":orx-noise"))
-    implementation(libs.openrndr.application)
-    implementation(libs.openrndr.math)
-}
+kotlin {
+    sourceSets {
+        val commonMain by getting {
+            dependencies {
+                implementation(libs.openrndr.application)
+            }
+        }
+        val jvmMain by getting {
+            dependencies {
+                implementation(project(":orx-noise"))
+                implementation(libs.gson)
+                implementation(libs.openrndr.math)
+            }
+        }
+
+        val jvmDemo by getting {
+            dependencies {
+                implementation(project(":orx-palette"))
+                implementation(project(":orx-palette"))
+                implementation(project(":orx-shapes"))
+            }
+        }
+    }
+}