Update python plugin example for compatibility with v0.100.0

Author: j1mr10rd4n

contributor-book/plugins.md

@@ -1020,8 +1020,8 @@ def signature():
     return {
         "sig": {
             "name": "len",
-            "usage": "calculates the length of its input",
-            "extra_usage": "",
+            "description": "calculates the length of its input",
+            "extra_description": "",
             "search_terms": [],
             "required_positional": [],
             "optional_positional": [],
@@ -1052,7 +1052,7 @@ def send_hello():
     hello = {
         "Hello": {
             "protocol": "nu-plugin",
-            "version": "0.90.2",
+            "version": "0.100.0",
             "features": []
         }
     }
@@ -1081,15 +1081,18 @@ def send_error(id, error_msg, span):
 
 def handle_call(id, call_info):
     try:
-        input = call_info["input"]["Value"]["String"]
+        input = call_info["input"]["Value"][0]["String"]
         output = {
             "PipelineData": {
-                "Value": {
-                    "Int": {
-                        "val": len(input["val"]),
-                        "span": input["span"]
-                    }
-                }
+                "Value": [
+                    {
+                        "Int": {
+                            "val": len(input["val"]),
+                            "span": input["span"]
+                        }
+                    },
+                    None
+                ]
             }
         }
         send_response(id, output)
@@ -1176,7 +1179,7 @@ def send_hello():
     hello = {
         "Hello": {
             "protocol": "nu-plugin",
-            "version": "0.90.2",
+            "version": "0.100.0",
             "features": []
         }
     }
@@ -1195,15 +1198,18 @@ When sent a `Run` request, we parse the supplied JSON and respond to the request
 ```python
 def handle_call(id, call_info):
     try:
-        input = call_info["input"]["Value"]["String"]
+        input = call_info["input"]["Value"][0]["String"]
         output = {
             "PipelineData": {
-                "Value": {
-                    "Int": {
-                        "val": len(input["val"]),
-                        "span": input["span"]
-                    }
-                }
+                "Value": [
+                    {
+                        "Int": {
+                            "val": len(input["val"]),
+                            "span": input["span"]
+                        }
+                    },
+                    None
+                ]
             }
         }
         send_response(id, output)