build: add windows build script

src/client/build.ps1

@@ -0,0 +1,26 @@
+$current_location = Get-Location
+$project_root = git rev-parse --show-toplevel
+Set-Location $project_root/src/client
+
+foreach ($opt in $args) {
+    switch ($opt) {
+        "--silent" { $silent = $true }
+        default {
+            Write-Host "Invalid option: $opt"
+            exit
+        }
+    }
+}
+
+if ($silent) { $log_level = "--log-level=warning" }
+
+if (!$silent) { Write-Host "Transpile and bundle TS sources to webui.js" }
+esbuild --bundle --target="chrome90,firefox90,safari15" --format=esm --tree-shaking=false --outdir=. ./webui.ts $log_level
+
+if (!$silent) { Write-Host "Convert JS source to C-String using xxd" }
+Set-Location ..
+# The path needs to match the path in webui.c, that's why we move up to src/
+xxd -i client/webui.js client/webui.h
+
+if (!$silent) { Write-Host "Finished." }
+Set-Location $current_location