feat: Initial clean release of CHM

packages/lib/CssUtils.ts

@@ -0,0 +1,26 @@
+import fs from 'fs-extra';
+
+export const loadCustomCss = async (filePath: string) => {
+	let cssString = '';
+	if (await fs.pathExists(filePath)) {
+		try {
+			cssString = await fs.readFile(filePath, 'utf-8');
+		} catch (error) {
+			let msg = error.message ? error.message : '';
+			msg = `Could not load custom css from ${filePath}\n${msg}`;
+			error.message = msg;
+			throw error;
+		}
+	}
+
+	return cssString;
+};
+
+export const injectCustomStyles = async (elementId: string, cssFilePath: string) => {
+	const css = await loadCustomCss(cssFilePath);
+	const styleTag = document.createElement('style');
+	styleTag.setAttribute('id', elementId);
+	styleTag.setAttribute('type', 'text/css');
+	styleTag.appendChild(document.createTextNode(css));
+	document.head.appendChild(styleTag);
+};