feat(json_schemas): Add dockerContextDir and changelog to actor schema (#584)

It's missing in the schema, although it's in the documentation:
https://docs.apify.com/platform/actors/development/actor-definition/actor-json#reference

Reported here:
https://apify.slack.com/archives/C0L33UM7Z/p1766044857082619

Note: I didn't set any `default` like `dockerfile` and `readme`
properties have, as it could be a breaking change (but it looks like in
the worker the default value is not taken into account)

Author: mfori

packages/json_schemas/schemas/actor.schema.json

@@ -40,10 +40,16 @@
       "type": "string",
       "default": "../Dockerfile"
     },
+    "dockerContextDir": {
+      "type": "string"
+    },
     "readme": {
       "type": "string",
       "default": "../README.md"
     },
+    "changelog": {
+      "type": "string"
+    },
     "minMemoryMbytes": {
       "type": "integer",
       "minimum": 128,

packages/json_schemas/src/actor.schema.ts

@@ -45,10 +45,16 @@ export const actorSchema = {
             type: 'string',
             default: '../Dockerfile',
         },
+        dockerContextDir: {
+            type: 'string',
+        },
         readme: {
             type: 'string',
             default: '../README.md',
         },
+        changelog: {
+            type: 'string',
+        },
         minMemoryMbytes: {
             type: 'integer',
             minimum: ACTOR_LIMITS.MIN_RUN_MEMORY_MBYTES,

test/actor_schema.test.ts

@@ -27,7 +27,9 @@ describe('actor.json', () => {
                     API_KEY: 'my-api-key',
                 },
                 dockerfile: '../Dockerfile',
+                dockerContextDir: './docker',
                 readme: '../README.md',
+                changelog: '../CHANGELOG.md',
                 minMemoryMbytes: 256,
                 maxMemoryMbytes: 1024,
                 input: {