Dev-build-windows. Build with simple_rc, which is a library to pack resource files.

Signed-off-by: fufesou <shuanglongchen@yeah.net>

content/dev/build/windows/_index.en.md

@@ -42,6 +42,8 @@ rust-bindgen depends on clang,  download [llvm](https://github.com/llvm/llvm-pro
 
 ## Build
 
+### Default
+
 ```sh
 git clone https://github.com/rustdesk/rustdesk
 cd rustdesk
@@ -50,3 +52,82 @@ mv sciter.dll target/debug
 cargo run
 ```
 
+### Pack resource files
+
+Rustdesk can pack resource files in one exe file.
+Then extract files to the installation directory when being installed.
+
+This design makes rustdesk run both simple mode(single exe file) and full mode(all files after been installed).
+
+To pack resource files, follow the steps:
+1. cd rustdesk
+2. mkdir `resources` directory
+3. put files to `resources`
+4. cargo build --features with_rc,<other features>
+
+Feature `with_rc` is introduced to pack and extract resource files.
+
+#### Lib `simple_rc`
+
+A lib named `simple_rc` is used to pack and extract resource files.
+
+##### Generate resource packed file
+The pack process workflow:
+1. Parse the specified directory tree.
+2. Exclude specified files.
+3. Read all file contents, save as byte arrays in source file(`rc.rs`), and remember file names.
+
+`simple_rc` accepts either a configuration file or a `Config` structure.
+
+1. Generate resource packed with configuration file.
+```
+fn generate(conf_file: &str) -> ResultType<()>
+```
+```
+# The output source file
+outfile = "src/rc.rs"
+
+# The resource config list.
+[[confs]]
+# The file or director to integrate.
+inc = "D:/projects/windows/RustDeskTempTopMostWindow/x64/Release/xxx"
+# The exclusions.
+exc = ["*.dll", "*.exe"]
+# The front path that will ignore for extracting.
+# ${OutputPath} = ${InstallDir} + (${inc} - ${suppressed_front})
+# The following config will make base output path to be "RustDeskTempTopMostWindow/x64/Release/xxx".
+suppressed_front = "D:/projects/windows"
+```
+
+2. Generate resource packed file with a `Config` structure:
+```
+fn generate_with_conf<'a>(conf: &'a Config) -> ResultType<()>
+
+...
+    generate_with_conf(&Config {
+        outfile: "src/rc.rs".to_owned(),
+        confs: vec![ConfigItem {
+            inc: "resources".to_owned(),
+            exc: vec![],
+            suppressed_front: "resources".to_owned(),
+        }],
+    })
+    .unwrap();
+...
+```
+
+##### Extract files
+
+Extraction will keep the resource direcotry tree.
+
+The extraction process workflow:
+1. Create directory if needed, to restore the directory tree.
+2. Write contents to the associated file names.
+
+```
+fn extract_resources(root_path: &str) -> ResultType<()>
+```
+
+##### Note
+
+File attributes like privileges, create time, owner, are not supported.