Merge pull request #9 from asigloo/feature/8-usage-documentation-

docs(usage): usage guide

Author: alvarosabu

docs/v3/guide/usage.md

@@ -1 +1,116 @@
-Coming soon. 😜
+## Form Composition
+
+The dynamic form component `<dynamic-form />` is pretty straight-forward. 😁
+
+You will only need to add it to your template like this:
+
+```html
+<template>
+  <dynamic-form :form="form" />
+</template>
+```
+
+And pass trough the `DynamicForm` object as a prop:
+
+```typescript
+setup() {
+  const form = ref({
+    id: 'my-awesome-form,
+    fields: {
+      name: TextField({
+        label: 'Name',
+      }),
+      email: EmailField({
+        label: 'Email',
+      }),
+      password: PasswordField({
+        label: 'Password',
+        autocomplete: 'current-password',
+        validations: [passwordValidator],
+      }),
+    }
+  });
+
+  return { form }
+}
+```
+
+If you're using [VueI18n](https://kazupon.github.io/vue-i18n/) or any property of your form fields for example: `customClass`, `options` needs to be reactive you can also declare the form as a `computed` property like this:
+
+```typescript
+import { useI18n } from "./i18nPlugin";
+
+setup() {
+  const i18n = useI18n();
+  let consoleOptions = ref([]);
+
+  const form = computed(() => ({
+    id: 'my-awesome-form,
+    fields: {
+      name: TextField({
+        label: i18n.t('name'),
+      }),
+      email: EmailField({
+        label: i18n.t('email'),
+      }),
+      console: SelectField({
+        label: 'Console (Async Options)',
+        optionValue: 'console',
+        options: consoleOptions.value,
+      }),
+    }
+  }));
+
+  onMounted(async () => {
+    try {
+      consoleOptions.value = await yourApiCall();
+    } catch (e) {
+      console.error(e);
+    }
+  });
+
+  return { form }
+}
+```
+
+## Submitting the form
+
+This is the recommended way to use the `dynamic-forms` with all the features. (Built-in Validations included).
+
+```html
+<template>
+  <div>
+    <dynamic-form
+      :form="form"
+      @submitted="formSubmitted"
+      @error="processErrrors"
+    />
+    <button submit="true" :form="form.id">
+      Submit
+    </button>
+  </div>
+</template>
+```
+
+## Values Changed
+
+The library provides you the possibility of submitting the form (check the previous section) or listen to the values change directly, using the `change` event.
+
+```html
+<template>
+  <dynamic-form :form="form" @change="updateValues" />
+</template>
+```
+
+```js
+methods: {
+  updateValues(values) {
+    // Apply your own validation
+    // Do what you need with the data
+  }
+}
+```
+
+::: warning
+By using `change` event, you are giving up to the built-in validation, which is only available if the form is submitted. You will need to apply the validation yourself or use the `error` event.
+:::