feat: enable --enable-libzimg (#574)

* feat: enable --enable-libzimg

* 📄 doc: comment the Dockerfile

* ⚙️ conf: modify CI to add zimg-dev

* ⚙️ conf: try to install and build from git zimg

* ⚙️ fix: git recursive

* ⚙️ conf: add zimg version display

* ⚙️ conf: change cache name to check if cache was responsible for build failure

* ⚙️ conf: change dockerfile to build zimg

* ➕ add: missing build script file zimg.sh

build/zimg.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+set -euo pipefail
+
+CONF_FLAGS=(
+  --prefix=$INSTALL_DIR            # lib installation directory
+  --host=x86_64-linux-gnu          # use i686 linux host
+  --disable-shared                 # build static library
+  --enable-static                  # enable static library
+  --disable-dependency-tracking    # speed up one-time build
+  --disable-simd                   # disable simd optimization
+)
+
+emconfigure ./autogen.sh
+
+emconfigure ./configure "${CONF_FLAGS[@]}"
+emmake make install -j