Add sift and rg for FZF_DEFAULT_COMMAND

Windows.md

@@ -13,12 +13,20 @@ To use relative filepaths, set `FZF_DEFAULT_COMMAND` to any of the following and
 
 - cmd.exe https://github.com/junegunn/fzf/pull/971#issuecomment-313971408
   ```dosbatch
-cmd.exe /q/V:ON/c "for /f %A in ('dir /s/b 2^> nul') do set RELPATH=%A & echo !RELPATH:%cd%\=!"
+  cmd.exe /q/V:ON/c "for /f %A in ('dir /s/b 2^> nul') do set RELPATH=%A && echo !RELPATH:%cd%\=!"
   ```
 - powershell https://github.com/junegunn/fzf/issues/960
   ```dosbatch
   powershell.exe -NoLogo -NoProfile -Noninteractive -Command "Get-ChildItem -File -Recurse -Name"
   ```
+- [sift](https://sift-tool.org/)
+  ```dosbatch
+  sift --targets . 2> nul
+  ```
+- [rg](https://github.com/BurntSushi/ripgrep) (supports UTF-16 as of [0.5.0](https://github.com/BurntSushi/ripgrep/blob/master/CHANGELOG.md#050-2017-03-12))
+  ```dosbatch
+  rg --files . 2> nul
+  ```
 
 ### PowerShell support