docs: update readme

Author: zhangxianbing1

README.md

@@ -1,3 +1,15 @@
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
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+
+- [jsonpath-python](#jsonpath-python)
+  - [Features](#features)
+  - [Examples](#examples)
+    - [Fields-Extractor](#fields-extractor)
+    - [Multi-selection and inverse-selection filtering](#multi-selection-and-inverse-selection-filtering)
+    - [Sorting by multiple fields, ascending and descending order](#sorting-by-multiple-fields-ascending-and-descending-order)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+
 # jsonpath-python
 
 A more powerful JSONPath implementations in modern python.
@@ -6,4 +18,134 @@ A more powerful JSONPath implementations in modern python.
 
 - [x] Light. (No need to install third-party dependencies.)
 - [ ] Support fields-extractor.
-- [ ] Support simple multi-selection and inverse-selection.
+- [ ] Support multi-selection and inverse-selection filtering.
+- [ ] Support sorting by multiple fields, ascending and descending order.
+
+## Examples
+
+JSON format data:
+
+```python
+data = {
+    "store": {
+        "book": [
+            {
+                "category": "reference",
+                "author": "Nigel Rees",
+                "title": "Sayings of the Century",
+                "price": 8.95
+            },
+            {
+                "category": "fiction",
+                "author": "Evelyn Waugh",
+                "title": "Sword of Honour",
+                "price": 12.99
+            },
+            {
+                "category": "fiction",
+                "author": "Herman Melville",
+                "title": "Moby Dick",
+                "isbn": "0-553-21311-3",
+                "price": 8.99
+            },
+            {
+                "category": "fiction",
+                "author": "J. R. R. Tolkien",
+                "title": "The Lord of the Rings",
+                "isbn": "0-395-19395-8",
+                "price": 22.99
+            }
+        ],
+        "bicycle": {
+            "color": "red",
+            "price": 19.95
+        }
+    }
+}
+```
+
+### Fields-Extractor
+
+```python
+>>> JSONPath("$.store.book[*][title,price]",result_type="FIELD").parse(data)
+```
+
+```json
+{
+  "store": {
+    "book": [
+      {
+        "title": "Sayings of the Century",
+        "price": 8.95
+      },
+      {
+        "title": "Sword of Honour",
+        "price": 12.99
+      },
+      {
+        "title": "Moby Dick",
+        "price": 8.99
+      },
+      {
+        "title": "The Lord of the Rings",
+        "price": 22.99
+      }
+    ]
+  }
+}
+```
+
+### Multi-selection and inverse-selection filtering
+
+```python
+>>> JSONPath("$.store.book[?(@.price>8.95 && @.price<=20 || @.title!='Sword of Honour')]").parse(data)
+```
+
+```json
+[
+  {
+    "category": "fiction",
+    "author": "Herman Melville",
+    "title": "Moby Dick",
+    "isbn": "0-553-21311-3",
+    "price": 8.99
+  }
+]
+```
+
+### Sorting by multiple fields, ascending and descending order
+
+```python
+>>> JSONPath("$.store.book[\category,/price]").parse(data)
+```
+
+```json
+[
+  {
+    "category": "reference",
+    "author": "Nigel Rees",
+    "title": "Sayings of the Century",
+    "price": 8.95
+  },
+  {
+    "category": "fiction",
+    "author": "Herman Melville",
+    "title": "Moby Dick",
+    "isbn": "0-553-21311-3",
+    "price": 8.99
+  },
+  {
+    "category": "fiction",
+    "author": "Evelyn Waugh",
+    "title": "Sword of Honour",
+    "price": 12.99
+  },
+  {
+    "category": "fiction",
+    "author": "J. R. R. Tolkien",
+    "title": "The Lord of the Rings",
+    "isbn": "0-395-19395-8",
+    "price": 22.99
+  }
+]
+```