docs: add Quickstart, Usage, and Troubleshooting guides for Core Module

Author: dzienisz

android-sdk/quickstart.mdx renamed to android-sdk/core-module/quickstart.mdx

@@ -1,9 +1,11 @@
 ---
 id: troubleshooting
-title: Troubleshooting
+title: Troubleshooting (Core Module)
 description: Troubleshooting Tolgee Android SDK
 ---
+
 #Troubleshooting (Core Module)
+
 ## Fast Checklist
 
 Before diving into troubleshooting, quickly review this list to steer clear of the most common erroes.
@@ -39,11 +41,14 @@ curl -I "https://cdn.tolg.ee/your-cdn-url-prefix/en.json"
 - For UI tests, inject a test Tolgee instance with preloaded data.
 
 ## Common Issues
+
 **1. Dependency Issues**
+
 - Make sure Maven Central is included in your repositories - check the dependency in your build.gradle.kts.
 - If using a Version Catalog, confirm that version.ref = "tolgee" points to the correct version.
 
 **2. Translation Issues**
+
 - Check that your Tolgee instance is properly initialized (in Application with applicationContext).
 - Verify CDN URL prefix in Tolgee Platform.
 - Check that your storage provider is properly configured
@@ -52,38 +57,41 @@ curl -I "https://cdn.tolg.ee/your-cdn-url-prefix/en.json"
 - Use tolgee.preload or tolgee.tFlow before calling tolgee.t to ensure translations are loaded.
 
 **3. Network Security Issues**
+
 - Add a network_security.xml in your res/xml folder (You can reference it in AndroidManifest.xml).
 
 **4. Locale Issues**
+
 - Use tolgee.changeFlow to monitor locale changes and update your UI accordingly.
 - Call tolgee.preload(this) function for critical screens (e.g., login, onboarding).
 - Verify that your project supports the locale code you're using.
 - Check that translations for the selected locale exist in your Tolgee project.
 - Use a mock or explicit instance for tests/previews.
 
-***5. Plurals & Formatting Issues**
+**\*5. Plurals & Formatting Issues**
+
 - Make sure plural resources exist both in Android (plurals.xml) and Tolgee Platform.
 - Use the correct formatter (Sprintf vs ICU).
 - Ensure translations in Tolgee Platform match the expected format style.
 
 See also: [Android XML format](/platform/formats/android_xml) · [Tolgee Universal ICU placeholders](/platform/translation_process/tolgee_universal_icu_placeholders)
 
-
 **6. Android Resource Integration Issues**
+
 - Check that your Android resources are properly structured - Tolgee is using resources.getResourceEntryName to find key for the resource.
 - Make sure the Tolgee instance has access to the Android application context.
 - Ensure that the TolgeeStorageProviderAndroid is properly initialized with the context and version code which changes with each app update.
 
 **7. Multiplatform (KMP) Issues**
+
 - Verify that your resource files are correctly set up and all strings present in resources are also in Tolgee Platform.
 - Make sure that you are using the correct resource references.
 
-
 ## Useful links
 
 - Installation: [Quickstart](./quickstart.mdx)
 - Usage (Views): [Usage](./usage.mdx)
 - For complete examples of how to use the Tolgee Core module, check out the demo projects:
-Traditional Android Views example - https://github.com/tolgee/tolgee-mobile-kotlin-sdk/tree/master/demo/exampleandroid
+  Traditional Android Views example - https://github.com/tolgee/tolgee-mobile-kotlin-sdk/tree/master/demo/exampleandroid
 - Jetpack Compose: [Installation](./jetpack/installation.mdx), [Usage](./jetpack/usage.mdx)
 - CLI for static strings: [Tolgee CLI](/tolgee-cli/installation)

android-sdk/troubleshooting.mdx renamed to android-sdk/core-module/troubleshooting.mdx

@@ -2,22 +2,25 @@ module.exports = {
   someSidebar: [
     'about',
     'get-started',
-    'quickstart',
-    'usage',
+    {
+      type: 'category',
+      label: 'Core Module',
+      items: [
+        'core-module/quickstart',
+        'core-module/usage',
+        'core-module/troubleshooting',
+      ],
+    },
+
     {
       type: 'category',
       label: 'Jetpack Compose',
-      link: {
-        type: 'doc',
-        id: 'jetpack/overview',
-      },
       items: [
         'jetpack/installation',
         'jetpack/usage',
         'jetpack/troubleshooting',
       ],
     },
     'reccomendations',
-    'troubleshooting',
   ],
 };