fix(docs): move a few API doc comments to descriptions (#15381)

Previously, the comments were being used as the summaries, and thus were
displayed as the “title” of these endpoints

open-api/immich-openapi-specs.json

@@ -1424,6 +1424,7 @@
     },
     "/assets/bulk-upload-check": {
       "post": {
+        "description": "Checks if assets exist by checksums",
         "operationId": "checkBulkUpload",
         "parameters": [],
         "requestBody": {
@@ -1459,7 +1460,7 @@
             "api_key": []
           }
         ],
-        "summary": "Checks if assets exist by checksums",
+        "summary": "checkBulkUpload",
         "tags": [
           "Assets"
         ]
@@ -1467,6 +1468,7 @@
     },
     "/assets/device/{deviceId}": {
       "get": {
+        "description": "Get all asset of a device that are in the database, ID only.",
         "operationId": "getAllUserAssetsByDeviceId",
         "parameters": [
           {
@@ -1504,7 +1506,7 @@
             "api_key": []
           }
         ],
-        "summary": "Get all asset of a device that are in the database, ID only.",
+        "summary": "getAllUserAssetsByDeviceId",
         "tags": [
           "Assets"
         ]
@@ -1512,6 +1514,7 @@
     },
     "/assets/exist": {
       "post": {
+        "description": "Checks if multiple assets exist on the server and returns all existing - used by background backup",
         "operationId": "checkExistingAssets",
         "parameters": [],
         "requestBody": {
@@ -1547,7 +1550,7 @@
             "api_key": []
           }
         ],
-        "summary": "Checks if multiple assets exist on the server and returns all existing - used by background backup",
+        "summary": "checkExistingAssets",
         "tags": [
           "Assets"
         ]
@@ -1903,6 +1906,7 @@
         ]
       },
       "put": {
+        "description": "Replace the asset with new file, without changing its id",
         "operationId": "replaceAsset",
         "parameters": [
           {
@@ -1956,7 +1960,7 @@
             "api_key": []
           }
         ],
-        "summary": "Replace the asset with new file, without changing its id",
+        "summary": "replaceAsset",
         "tags": [
           "Assets"
         ],