Add support for task options

Added support for customizing processors in `scripts.js` (esbuild), `styles.js` (node-sass, postcss, autoprefixer), and `svgs.js` (svg-mixer), via arguments for the exported task functions.

Added:
- Constants to decouple shared default options, options for development, and options for production.
- Constants to export default options for development and production as an array of arguments to pass to task functions.

Changed:
- watch.js to apply development args to tasks

build/tasks/svgs.js

@@ -5,13 +5,48 @@ import template from '../utils/template.js';
 import { basename } from 'node:path';
 import mixer from 'svg-mixer';
 
+/**
+ * @const {object} defaultMixerOptions     - The default shared Mixer options.
+ * @const {object} developmentMixerOptions - The predefined Mixer options for development.
+ * @const {object} productionMixerOptions  - The predefined Mixer options for production.
+ */
+export const defaultMixerOptions = {
+    spriteConfig: {
+        usages: false,
+    },
+};
+export const developmentMixerOptions = Object.assign({}, defaultMixerOptions);
+export const productionMixerOptions  = Object.assign({}, defaultMixerOptions);
+
+/**
+ * @const {object} developmentSVGsArgs - The predefined `compileSVGs()` options for development.
+ * @const {object} productionSVGsArgs  - The predefined `compileSVGs()` options for production.
+ */
+export const developmentSVGsArgs = [
+    developmentMixerOptions,
+];
+export const productionSVGsArgs  = [
+    productionMixerOptions,
+];
+
 /**
  * Generates and transforms SVG spritesheets.
  *
  * @async
+ * @param  {object} [mixerOptions=null] - Customize the Mixer API options.
+ *     If `null`, default production options are used.
  * @return {Promise}
  */
-export default async function compileSVGs() {
+export default async function compileSVGs(mixerOptions = null) {
+    if (mixerOptions == null) {
+        mixerOptions = productionMixerOptions;
+    } else if (
+        mixerOptions !== developmentMixerOptions &&
+        mixerOptions !== productionMixerOptions
+    ) {
+        mixerOptions = Object.assign({}, defaultMixerOptions, mixerOptions);
+    }
+
     loconfig.tasks.svgs.forEach(async ({
         includes,
         outfile
@@ -25,11 +60,7 @@ export default async function compileSVGs() {
             includes = includes.map((path) => template(path));
             outfile  = template(outfile);
 
-            const result = await mixer(includes, {
-                spriteConfig: {
-                    usages: false
-                }
-            });
+            const result = await mixer(includes, mixerOptions);
 
             await result.write(outfile);