Add initial height for bottom side.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tp/tp-splitter",
-  "version": "1.7.1",
+  "version": "1.8.0",
   "description": "",
   "main": "tp-splitter.js",
   "scripts": {

tp-hsplitter.js

@@ -66,6 +66,7 @@ class TpHSplitter extends LitElement {
       minSideHeight: { type: Number },
       lateResize: { type: Boolean },
       initialTopHeight: { type: String },
+      initialBottomHeight: { type: String },
     };
   }
 
@@ -92,6 +93,8 @@ class TpHSplitter extends LitElement {
   firstUpdated() {
     if (this.initialTopHeight) {
       this.style.gridTemplateRows = `${this.initialTopHeight} var(--tp-splitter-width, 5px) 1fr`;
+    } else if (this.initialBottomHeight) {
+      this.style.gridTemplateRows = `1fr var(--tp-splitter-width, 5px) ${this.initialBottomHeight}`;
     }
   }