Implement the SVGR and SVGO configuration files

All configurations for SVGR are set in the `svgr.config.js` file instead
of passing them to the corresponding Gatsby plugin for the Webpack
loader.

- `expandProps` = `end` - ensure props are always spread
  (`{...props}`) last on the root `<svg>` element.
- `ext` = `jsx` - use the JSX file extension for generated components.
- `icon` = `false` - ensure the `width` and `height` props (hardcoded
  `1em` value) are not added.
- `ref` = `true` - export components using React's `forwardRef` API to
  reference the underlying component and allow access to the root SVG
  element which is necessary for animations.
- `svgo` = `false` - all SVG files in this project are already
  optimized with SVGO using the included `.svgo.yml` configuration.

The configuration for SVGO is implemented in the `.svgo.yml` file that
is also placed in the project root and will be picked up by SVGO
automatically.

GH-72

.svgo.yml

@@ -0,0 +1,17 @@
+# Copyright (C) 2018-present Arctic Ice Studio <[email protected]>
+# Copyright (C) 2018-present Sven Greb <[email protected]>
+#
+# Project:    Nord Docs
+# Repository: https://github.com/arcticicestudio/nord-docs
+# License:    MIT
+
+# Configuration for SVGO.
+#
+# References:
+# - https://github.com/svg/svgo
+# - https://github.com/svg/svgo/blob/master/.svgo.yml
+
+multipass: true
+js2svg:
+  pretty: true
+  indent: 2

svgr.config.js

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2018-present Arctic Ice Studio <[email protected]>
+ * Copyright (C) 2018-present Sven Greb <[email protected]>
+ *
+ * Project:    Nord Docs
+ * Repository: https://github.com/arcticicestudio/nord-docs
+ * License:    MIT
+ */
+
+/**
+ * @file The SVGR configuration.
+ * @author Arctic Ice Studio <[email protected]>
+ * @author Sven Greb <[email protected]>
+ * @see https://www.smooth-code.com/open-source/svgr/docs/configuration-files
+ * @see https://www.smooth-code.com/open-source/svgr/docs/options
+ * @since 0.3.0
+ */
+
+module.exports = {
+  /* Always spread props (`{...props}`) last on the root `<svg>` element. */
+  expandProps: "end",
+
+  /* Use the JSX file extension for generated components. */
+  ext: "jsx",
+
+  /*  Don't add the `width` and `height` props (hardcoded `1em` value). */
+  icon: false,
+
+  /*
+   * Export components using React's `forwardRef` API to reference the underlying component and allow access to the
+   * root `<svg>` element which is necessary for animations.
+   */
+  ref: true,
+
+  /* All SVG files in this project are already optimized with SVGO using the included `.svgo.yml` configuration. */
+  svgo: false
+};