fix: errors related to language names

Author: qubka

content/4.languages/5.golang/2.first-plugin.md

@@ -93,7 +93,7 @@ Each plugin in the **Plugify** framework requires a **manifest file** with the `
   "entryPoint": "bin/go_example_plugin.dll",
   "supportedPlatforms": [],
   "languageModule": {
-    "name": "go"
+    "name": "golang"
   },
   "dependencies": [],
   "exportedMethods": []

content/4.languages/7.dlang/2.first-plugin.md

@@ -86,7 +86,7 @@ Each plugin in the **Plugify** framework requires a **manifest file** with the `
   "entryPoint": "bin/d_example_plugin.dll",
   "supportedPlatforms": [],
   "languageModule": {
-    "name": "d"
+    "name": "dlang"
   },
   "dependencies": [],
   "exportedMethods": []

content/ru/4.languages/5.golang/2.first-plugin.md

@@ -93,7 +93,7 @@ tree:
   "entryPoint": "bin/go_example_plugin.dll",
   "supportedPlatforms": [],
   "languageModule": {
-    "name": "go"
+    "name": "golang"
   },
   "dependencies": [],
   "exportedMethods": []