add a simple text file reader

app/src/main/kotlin/com/simplemobiletools/filemanager/activities/ReadTextActivity.kt

@@ -0,0 +1,22 @@
+package com.simplemobiletools.filemanager.activities
+
+import android.os.Bundle
+import com.simplemobiletools.filemanager.R
+import com.simplemobiletools.filemanager.extensions.config
+import kotlinx.android.synthetic.main.activity_read_text.*
+import java.io.File
+
+class ReadTextActivity : SimpleActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_read_text)
+
+        read_text_view.setTextColor(config.textColor)
+        val uri = intent.data
+        if (uri.scheme == "file") {
+            read_text_view.text = File(uri.path).readText()
+        } else {
+            read_text_view.text = contentResolver.openInputStream(uri).bufferedReader().use { it.readText() }
+        }
+    }
+}