Add alignment note as per https://github.com/orgs/espruino/discussions/3596#discussioncomment-13196482

modules/Layout.md

@@ -3,6 +3,8 @@ Bangle.js Layout Library
 
 > Take a look at README.md for hints on developing with this library.
 
+**Please see more complete documentation at https://www.espruino.com/Bangle.js+Layout**
+
 Usage
 -----
 
@@ -85,6 +87,40 @@ Other functions:
 - `layout.setUI()` - Re-add any UI input handlers
 
 
+Alignment
+----------
+
+You can align elements within their `h` or `v` containers with `halign` and `valign`, however within an element, text is always rendered centered.
+
+As a result, if you want to align text, you shouldn't use `fillx:1` in the text element as the element will then fill to all available space and won't align.
+
+```JS
+var layout = new Layout( {
+    type:"v", c: [{
+        type:"txt",
+        font:"20%",
+        fillx:0, // must be 0 for halign to work
+        filly:1,
+        halign:-1, // LEFT align
+        label:"Left"
+      }, {
+        type:"txt",
+        font:"20%",
+        fillx:0,
+        filly:1,
+        halign:0, // CENTER align
+        label:"Center"
+      }, {
+        type:"txt",
+        font:"20%",
+        fillx:0,
+        filly:1,
+        halign:1, // CERIGHTNTER align
+        label:"Right"},
+    ]
+});
+```
+
 Using with `E.showMenu`/`E.showPrompt`/etc
 --------------------------------------