resolveLexicon endpoint (#4227)

* Add resolveLexicon.json for lexicon resolution

* Update lexicons/com/atproto/lexicon/resolveLexicon.json

* chore: formatting and linting

* chore: Adding changeset information

* documentation: Updating descriptions for properties.

* refactor: Updating com.atproto.lexicon.resolveLexicon lexicon schema from PR discussion and feedback

* Update lexicons/com/atproto/lexicon/resolveLexicon.json

Co-authored-by: Nick Gerakines <[email protected]>

* tweak changeset

* lexicon codegen

---------

Co-authored-by: Nick Gerakines <[email protected]>
Co-authored-by: Matthieu Sieben <[email protected]>

Author: 3 people

.changeset/bright-falcons-applaud.md

@@ -0,0 +1,5 @@
+---
+"@atproto/api": minor
+---
+
+Introduce `com.atproto.lexicon.resolveLexicon` lexicon method

lexicons/com/atproto/lexicon/resolveLexicon.json

@@ -0,0 +1,51 @@
+{
+  "lexicon": 1,
+  "id": "com.atproto.lexicon.resolveLexicon",
+  "defs": {
+    "main": {
+      "type": "query",
+      "description": "Resolves an atproto lexicon (NSID) to a schema.",
+      "parameters": {
+        "type": "params",
+        "properties": {
+          "nsid": {
+            "format": "nsid",
+            "type": "string",
+            "description": "The lexicon NSID to resolve."
+          }
+        },
+        "required": ["nsid"]
+      },
+      "output": {
+        "encoding": "application/json",
+        "schema": {
+          "type": "object",
+          "properties": {
+            "cid": {
+              "type": "string",
+              "format": "cid",
+              "description": "The CID of the lexicon schema record."
+            },
+            "schema": {
+              "type": "ref",
+              "ref": "com.atproto.lexicon.schema#main",
+              "description": "The resolved lexicon schema record."
+            },
+            "uri": {
+              "type": "string",
+              "format": "at-uri",
+              "description": "The AT-URI of the lexicon schema record."
+            }
+          },
+          "required": ["uri", "cid", "schema"]
+        }
+      },
+      "errors": [
+        {
+          "description": "No lexicon was resolved for the NSID.",
+          "name": "LexiconNotFound"
+        }
+      ]
+    }
+  }
+}