docs: add basic usage to README.md

Author: kevinkosterr

README.md

@@ -1,2 +1,89 @@
 # Vue 3 Form Generator
-A Vue 3 version of `vue-form-generator`, a schema-based form generator.
+A Vue 3 version of `vue-form-generator`, a schema-based form generator.
+
+## Basic usage
+1. Install plugin in your Vue app, this will make all necessary components globally available in your app.
+```javascript
+// ...
+
+import VueFormGenerator from 'vue3-form-generator'
+
+app.use(VueFormGenerator)
+
+// ...
+```
+2. Define a schema inside your Vue component
+<br><br>
+#### Composition API:
+```vue
+<template>
+  <vue-form-generator :schema="form.schema" :model="form.model"/>
+</template>
+
+<script setup>
+  import { ref } from 'vue'
+  
+  const form = ref({
+    model: {
+      name: '',
+      terms: false,
+    },
+    schema: {
+      fields: [
+        {
+          name: 'name',
+          label: 'Name',
+          type: 'input',
+          inputType: 'text',
+          model: 'name',
+          placeholder: "Write name...",
+          readonly: false,
+          required: true,
+        },
+        {
+          name: 'terms',
+          label: 'Accept terms and conditions',
+          type: 'input',
+          inputType: 'checkbox',
+          model: 'terms',
+        }
+      ]
+    }
+  })
+</script>
+```
+#### Options API:
+```vue
+<template>
+  <vue-form-generator :schema="form.schema" :model="form.model"/>
+</template>
+
+<script>
+  export default {
+    data () {
+      return {
+        form: {
+          model: {
+            name: '',
+          },
+          schema: {
+            fields: [
+              {
+                name: 'name',
+                label: 'Name',
+                type: 'input',
+                inputType: 'text',
+                model: 'name',
+                placeholder: "Write name...",
+                readonly: false,
+                required: true,
+              }
+            ]
+          }
+        }
+      }
+    }
+  }
+</script>
+```
+

src/index.js

@@ -1,5 +1,6 @@
 import { setMessages } from "@/validators/messages.js";
 import { isObject } from "@/helpers";
+import { abstractField } from "@/mixins";
 
 import FormGenerator from "@/FormGenerator.vue";
 import FormGeneratorFields from "@/fields"
@@ -25,4 +26,7 @@ const VueFormGenerator = {
   validators
 }
 
-export default VueFormGenerator;
+export default VueFormGenerator
+export {
+  abstractField
+}