Introduced Dockerfile.dev, updated CONTRIBUTING

Dockerfile.dev can be used as a separate development environment for
anyone that does not wish to install the dependencies locally.

CONTRIBUTING.md

@@ -128,6 +128,32 @@ The following steps are tested on an Ubuntu system.
 
 14. Once things look perfect, We merge it to the ```dev``` branch and make it ready for the next version.
 
+## Development in Docker container
+
+If you prefer working within a Docker container as your development environment, you can do the following:
+
+1. Fork 🐸TTS[https://github.com/coqui-ai/TTS] by clicking the fork button at the top right corner of the project page.
+
+2. Clone 🐸TTS and add the main repo as a new remote named ```upsteam```.
+
+    ```bash
+    $ git clone git@github.com:<your Github name>/TTS.git
+    $ cd TTS
+    $ git remote add upstream https://github.com/coqui-ai/TTS.git
+    ```
+
+3. Build the Docker Image as your development environment (it installs all of the dependencies for you):
+
+    ```
+    docker build --tag=tts-dev:latest -f .\dockerfiles\Dockerfile.dev .
+    ```
+
+4. Run the container with GPU support:
+
+    ```
+    docker run -it --gpus all tts-dev:latest /bin/bash
+    ```
+
 Feel free to ping us at any step you need help using our communication channels.
 
 If you are new to Github or open-source contribution, These are good resources.

dockerfiles/Dockerfile.dev

@@ -0,0 +1,44 @@
+ARG BASE=nvidia/cuda:11.8.0-base-ubuntu22.04
+FROM ${BASE}
+
+# Install OS dependencies:
+RUN apt-get update && apt-get upgrade -y
+RUN apt-get install -y --no-install-recommends \
+    gcc g++ \
+    make \
+    python3 python3-dev python3-pip python3-venv python3-wheel \
+    espeak-ng libsndfile1-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Major Python Dependencies:
+RUN pip3 install llvmlite --ignore-installed
+RUN pip3 install torch torchaudio --extra-index-url https://download.pytorch.org/whl/cu118
+RUN rm -rf /root/.cache/pip
+
+WORKDIR /root
+
+# Copy Dependency Lock Files:
+COPY \
+    Makefile \
+    pyproject.toml \
+    setup.py \
+    requirements.dev.txt \
+    requirements.ja.txt \
+    requirements.notebooks.txt \
+    requirements.txt \
+    /root/
+
+# Install Project Dependencies
+# Separate stage to limit re-downloading:
+RUN pip install \
+    -r requirements.txt \
+    -r requirements.dev.txt \
+    -r requirements.ja.txt \
+    -r requirements.notebooks.txt
+
+# Copy TTS repository contents:
+COPY . /root
+
+# Installing the TTS package itself:
+RUN make install
+