docs(README): add pipx install instructions

README.md

@@ -21,9 +21,19 @@ For faster results, it is recommended to use a GPU with CUDA support.
 Install the latest version from the repository:
 ```shell
 pip install 'git+https://github.com/andreabak/whispersubs.git'
-# or with CUDA libraries for GPU acceleration
+```
+Or with CUDA libraries for GPU acceleration:
+```shell
 pip install 'whispersubs[cuda] @ git+https://github.com/andreabak/whispersubs.git'
 ```
+Or using pipx to install globally in an isolated environment:
+```shell
+pipx install 'git+https://github.com/andreabak/whispersubs.git'
+```
+Or with pipx and CUDA libraries for GPU acceleration:
+```shell
+pipx install 'whispersubs[cuda] @ git+https://github.com/andreabak/whispersubs.git'
+```
 
 ## Usage
 WhisperSubs can be used from the command line. The basic usage requires an input file, which will be the source for the transcription. The output will be a subtitle file in the SRT format in the same directory as the input file. The language will be automatically detected.