Update Dockerfile to node8-alpine, fix typos

Dockerfile

@@ -1,33 +1,33 @@
-FROM node:7-alpine
+FROM node:8-alpine
 LABEL description="Alpine image to build nativfier apps"
 
-### Install wine depedency
+### Dependencies
 RUN apk add --no-cache \
     wine \
     freetype \
     imagemagick \
     ### make symbolic link to use `wine`
     && ln -s /usr/bin/wine64 /usr/bin/wine
-    
+
 # Add sources
 COPY . /nativefier
 
 ### Build app package for nativefier installation
 RUN cd /nativefier/app && npm install \
     # Build and install nativefier binary
-    && cd /nativefier && npm install && npm run build && npm install -g \
-    ## Remove no longer needed sources
-    && rm -rf /nativefier
-
+    && cd /nativefier && npm install && npm run build \
+    # Expose globally
+    && npm link
 
 ### Use 1000 as default user not root
 USER 1000
 
-### Check that installation was sucessfull and chache all electron installation.
-### Ensures that no addtional download will needed at runtime exectuion `docker run`.
+### Check that installation was sucessful and cache electron installations.
+### Ensures that no addtional download will be needed at `docker run` runtime.
 RUN nativefier https://github.com/jiahaog/nativefier /tmp/nativefier \
     && nativefier -p osx https://github.com/jiahaog/nativefier /tmp/nativefier \
-# TODO: windows are currently not possible, because of non 64-bit `node-rcedit`, see https://github.com/electron/node-rcedit/issues/22.
+# TODO: windows are currently not possible, because of non 64-bit `node-rcedit`,
+#       see https://github.com/electron/node-rcedit/issues/22.
 #    && nativefier -p windows https://github.com/jiahaog/nativefier /tmp/nativefier \
     #remove not need test aplication
     && rm -rf /tmp/nativefier

README.md

@@ -121,15 +121,15 @@ See [Development](docs/development.md).
 
 ## Docker Image
 
-The [Dockerfile](Dockerfile) is designed that you can use it like the "normal" nativefier app. By default the command `nativefier --version` will be executed. Before you can use the Image you have to build it like follow:
+The [Dockerfile](Dockerfile) is designed to be used like the "normal" nativefier app. By default, the command `nativefier --help` will be executed. Before you can use the image you have to build it like follow:
 
     docker build -t local/nativefier .
 
-After that you can build your first nativefier app to the local `$TARGET-PATH`. Please ensure that you have write access to the `$TARGET-PATH`:
+After that, you can build your first nativefier app to the local `$TARGET-PATH`. Ensure you have write access to the `$TARGET-PATH`:
 
     docker run -v $TARGET-PATH:/target local/nativefier https://my-web-app.com/ /target/
-    
-You can also use additional source or nativefier options like e.g. use a icon:
+
+You can also pass nativefier flags, and mount additional volumes to provide local files. For example, to use a icon:
 
     docker run -v $PATH_TO_ICON/:/src -v $TARGET-PATH:/target local/nativefier --icon /src/icon.png --name whatsApp -p linux -a x64 https://my-web-app.com/ /target/