chore: 更新构建配置和依赖

- 更新app/build.gradle.kts构建配置
- 更新libs.versions.toml版本配置
- 更新.gitignore忽略规则
- 新增keystore.properties.template模板文件

app-android/gradle/libs.versions.toml

@@ -17,6 +17,7 @@ permissions = "0.34.0"
 coroutines = "1.9.0"
 serialization = "1.7.3"
 coil = "2.5.0"
+markdown = "0.22.0"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -66,6 +67,9 @@ kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-
 # Image Loading
 coil-compose = { group = "io.coil-kt", name = "coil-compose", version.ref = "coil" }
 
+# Markdown Rendering
+markdown-renderer = { group = "com.mikepenz", name = "multiplatform-markdown-renderer-m3", version.ref = "markdown" }
+
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
 kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }