Type some functions in terminal code

src/vs/workbench/parts/terminal/electron-browser/terminalConfigHelper.ts

@@ -87,7 +87,7 @@ export class TerminalConfigHelper {
 	 * Set the terminal font to `terminal.integrated.fontFamily` if it is set, otherwise fallback to
 	 * `editor.fontFamily`.
 	 */
-	public getFontFamily() {
+	public getFontFamily(): string {
 		let terminalConfig = this.configurationService.getConfiguration<ITerminalConfiguration>();
 		let fontFamily = terminalConfig.terminal.integrated.fontFamily;
 		if (!fontFamily) {

src/vs/workbench/parts/terminal/electron-browser/terminalPanel.ts

@@ -169,7 +169,7 @@ export class TerminalPanel extends Panel {
 		});
 	}
 
-	private setTerminalTheme() {
+	private setTerminalTheme(): void {
 		if (!this.terminal) {
 			return;
 		}
@@ -181,7 +181,7 @@ export class TerminalPanel extends Panel {
 	 * Set the terminal font to `terminal.integrated.fontFamily` if it is set, otherwise fallback to
 	 * `editor.fontFamily`.
 	 */
-	private setTerminalFont() {
+	private setTerminalFont(): void {
 		this.terminalDomElement.style.fontFamily = this.configurationHelper.getFontFamily();
 	}