Add Alpine Linux build system

Add Dockerfiles for building curl-impersonate on Alpine Linux.

The Dockerfile template file was modified to support Alpine Linux,
mainly by changing the dependency installation from 'apt' to 'apk'.
The resulting alpine images are small (~11mb) and will be uploaded to
Docker hub.

chrome/Dockerfile

@@ -15,14 +15,13 @@ WORKDIR /build
 RUN apt-get update && \
     apt-get install -y git ninja-build cmake curl zlib1g-dev
 
-
-# Dependencies for downloading and building BoringSSL
-RUN apt-get install -y g++ golang-go unzip
-
 # The following are needed because we are going to change some autoconf scripts,
 # both for libnghttp2 and curl.
 RUN apt-get install -y autoconf automake autotools-dev pkg-config libtool
 
+# Dependencies for downloading and building BoringSSL
+RUN apt-get install -y g++ golang-go unzip
+
 # Download and compile libbrotli
 ARG BROTLI_VERSION=1.0.9
 RUN curl -L https://github.com/google/brotli/archive/refs/tags/v${BROTLI_VERSION}.tar.gz -o brotli-${BROTLI_VERSION}.tar.gz && \
@@ -32,7 +31,6 @@ RUN cd brotli-${BROTLI_VERSION} && \
     cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./installed .. && \
     cmake --build . --config Release --target install
 
-
 # BoringSSL doesn't have versions. Choose a commit that is used in a stable
 # Chromium version.
 ARG BORING_SSL_COMMIT=3a667d10e94186fd503966f5638e134fe9fb4080
@@ -50,7 +48,7 @@ RUN cd boringssl && \
     ninja
 
 # Fix the directory structure so that curl can compile against it.
-# See https://everything.curl.dev/source/build/tls/boringssl 
+# See https://everything.curl.dev/source/build/tls/boringssl
 RUN mkdir boringssl/build/lib && \
     ln -s ../crypto/libcrypto.a boringssl/build/lib/libcrypto.a && \
     ln -s ../ssl/libssl.a boringssl/build/lib/libssl.a && \