Fix alignment problem in code block (#45)

In rendered HTML, the line number should be right aligned, and
code should be left aligned accordingly.

In addition, this patch added the basic build instructions, so that
someone can generated the PDF and HTML files.

Close #44

Makefile

@@ -8,16 +8,17 @@ $(PROJ).pdf: lkmpg.tex
 	pdflatex -shell-escape $< 2>/dev/null >/dev/null
 
 html: lkmpg.tex html.cfg
-	make4ht --shell-escape --utf8 --format html5 --config html.cfg --output-dir html lkmpg.tex
-	ln -sf lkmpg.html html/index.html
-	rm -f  lkmpg.xref lkmpg.tmp lkmpg.html lkmpg.css lkmpg.4ct lkmpg.4tc lkmpg.dvi lkmpg.lg lkmpg.idv lkmpg*.svg lkmpg.log lkmpg.aux 
+	sed $ 's/\t/    /g' lkmpg.tex > lkmpg-for-ht.tex
+	make4ht --shell-escape --utf8 --format html5 --config html.cfg --output-dir html  lkmpg-for-ht.tex
+	ln -sf lkmpg-for-ht.html html/index.html
+	rm -f  lkmpg-for-ht.tex lkmpg-for-ht.xref lkmpg-for-ht.tmp lkmpg-for-ht.html lkmpg-for-ht.css lkmpg-for-ht.4ct lkmpg-for-ht.4tc lkmpg-for-ht.dvi lkmpg-for-ht.lg lkmpg-for-ht.idv lkmpg*.svg lkmpg-for-ht.log lkmpg-for-ht.aux
+	rm -rf _minted-$(PROJ) _minted-lkmpg-for-ht
 
 indent:
 	(cd examples; find . -name '*.[ch]' | xargs clang-format -i)
 
 clean:
 	rm -f *.dvi *.aux *.log *.ps *.pdf *.out lkmpg.bbl lkmpg.blg lkmpg.lof lkmpg.toc
-	rm -rf _minted-lkmpg
 	rm -rf html
 
-.PHONY: html
+.PHONY: html

README.md

@@ -6,6 +6,58 @@ The guide has been around since 2001 and most copies of it on the web only descr
 The book can be freely accessed via https://sysprog21.github.io/lkmpg/ or [latest PDF file](https://github.com/sysprog21/lkmpg/releases).
 The original guide may be found at [Linux Documentation Project](http://www.tldp.org/LDP/lkmpg/).
 
+## Getting Started
+
+### Compile on Local Machine
+
+To prepare for build this book on your local machine, we're going to have make, TeXLive (MacTeX), dvipng and latexmk installed. On various Unix/Linux operating systems, this can be done simply by:
+
+```bash
+# Debian / Ubuntu
+$ sudo apt install make texlive-full latexmk dvipng
+
+# Arch / Manjaro
+$ sudo pacman -S make texlive-most texlive-bin dvipng
+
+# macOS
+$ brew install --cask mactex
+$ sudo tlmgr update --self && sudo tlmgr install dvipng latexmk
+```
+
+Now we could build document with following commands:
+
+```bash
+# download project
+$ git clone https://github.com/sysprog21/lkmpg.git && cd lkmpg
+
+# run commands
+$ make all              # compile pdf document
+$ make html             # convert to HTML
+$ make clean            # delete generated files
+```
+
+### Compile with Docker
+
+The compile process could be run completely using Docker. **Using Docker is recommended, as it guarantees the same dependencies with our GitHub Actions wokrflow.
+
+After [install docker engine](https://docs.docker.com/engine/install/) on your machine, pulling the docker image [twtug/lkmpg](https://hub.docker.com/r/twtug/lkmpg) and compile with it.
+
+Execute followings
+
+```bash
+# download project
+$ git clone https://github.com/sysprog21/lkmpg.git && cd lkmpg
+
+# pull docker image and run it as container
+$ docker pull twtug/lkmpg
+$ docker run --rm -it -v $(pwd):/workdir twtug/lkmpg
+
+# run commands
+$ make all              # compile pdf document
+$ make html             # convert to HTML
+$ make clean            # delete generated files
+```
+
 ## License
 
 The Linux Kernel Module Programming Guide is a free book; you may reproduce and/or modify it under the terms of the [Open Software License](https://opensource.org/licenses/OSL-3.0).

examples/procfs4.c

@@ -114,4 +114,4 @@ static void __exit procfs4_exit(void)
 module_init(procfs4_init);
 module_exit(procfs4_exit);
 
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL");

html.cfg

@@ -24,24 +24,21 @@
     vertical-align: top;
 }}
 
+\Css{pre.fancyvrb, {
+    white-space: pre;
+}}
+
 \Css{figure, .fancyvrb, .verbatim {
     margin-inline: 0;
     overflow-x: auto;
 }}
 
-\Css{.ecrm-0500 { 
+\Css{.ecrm-0500 {
     font-size: 70\%;
-    font-style: italic; 
+    font-style: italic;
     color: gray;
-    -webkit-user-select: none;
-    -moz-user-select: none;
-    -o-user-select: none;
-    user-select: none;
-}}
-
-\Css{.ecrm-0500:after {
-    content:" ";
-    white-space: pre;
+    width: 1.5rem;
+    display: inline-block;
     -webkit-user-select: none;
     -moz-user-select: none;
     -o-user-select: none;