feat: Implement OpenAPI types and EndpointPath class

- Added OpenAPI types in Core.types.ts to define the structure of OpenAPI specifications.
- Created EndpointPath class to manage API endpoint paths, including methods to set summary, description, parameters, and servers.
- Developed tests for complex API structures, endpoint path creation, external documentation, JSON schema dialect, server settings, and tag management.
- Ensured comprehensive coverage for the new features with multiple test cases.

Author: GroophyLifefor

deno.json

@@ -1,15 +1,16 @@
 {
   "name": "@murat/openapi",
   "exports": "./mod.ts",
-  "version": "0.1.3",
+  "version": "0.1.4",
   "tasks": {
     "lint": "deno lint",
     "test": "deno test --allow-all",
     "test:coverage-html": "deno test --allow-all --coverage=coverage && deno coverage coverage",
     "fmt": "deno fmt"
   },
   "imports": {
-    "@eemeli/yaml": "jsr:@eemeli/yaml@^2.7.1"
+    "@eemeli/yaml": "jsr:@eemeli/yaml@^2.7.1",
+    "@std/assert": "jsr:@std/assert@^1.0.13"
   },
   "license": "MIT"
 }