feat(file_system): Update example to include built+bundled file system (#268)

* feat(file_system): Update example to include built+bundled file system

* readme: update

Author: finger563

components/file_system/example/README.md

@@ -26,5 +26,5 @@ See the Getting Started Guide for full steps to configure and use ESP-IDF to bui
 
 ## Example Output
 
-![CleanShot 2024-07-01 at 13 57 50](https://github.com/esp-cpp/espp/assets/213467/dd45e8eb-6927-403b-a889-86274cfeeb76)
+![CleanShot 2024-07-02 at 10 09 29](https://github.com/esp-cpp/espp/assets/213467/02fab9cb-ec32-4ff5-93c9-1da7945ed2fc)
 

components/file_system/example/files/dir1/file3.txt

@@ -0,0 +1 @@
+hello world!

components/file_system/example/files/dir1/sub1/file2.txt

@@ -0,0 +1 @@
+hello world!

components/file_system/example/files/dir2/file4.txt

@@ -0,0 +1 @@
+hello world!

components/file_system/example/files/dir3/file5.txt

@@ -0,0 +1 @@
+hello world!

components/file_system/example/files/file1.txt

@@ -0,0 +1 @@
+hello world!

components/file_system/example/main/CMakeLists.txt

@@ -1,2 +1,6 @@
 idf_component_register(SRC_DIRS "."
                        INCLUDE_DIRS ".")
+
+# Note: you must have a partition named the first argument (here it's "littlefs")
+# in your partition table csv file.
+littlefs_create_partition_image(littlefs ../files FLASH_IN_PROJECT)

components/file_system/src/file_system.cpp

@@ -215,11 +215,14 @@ std::string FileSystem::list_directory(const std::string &path, const ListConfig
     if (config.date_time) {
       result += fmt::format("{:>12} ", get_file_time_as_string(file_path));
     }
-    result += prefix;
-    result += entry->d_name;
+    std::string relative_name = "";
+    if (prefix.size())
+      relative_name += prefix + "/";
+    relative_name += entry->d_name;
+    result += relative_name;
     result += "\r\n";
     if (config.recursive && fs::is_directory(file_status)) {
-      result += list_directory(file_path, config, std::string{entry->d_name} + "/");
+      result += list_directory(file_path, config, relative_name);
     }
   }
   closedir(dir);