Src README: Fix Book Links

Amend all reference links to point to the new standalone book:

    /docs/download/Git-Book.html

Improve description of `rake publish` output, providing links to both
local and online files.

docs_src/README.md

@@ -52,13 +52,19 @@ This folder contains the AsciiDoc sources of the English translation of the _Git
 
 # Developers' Notes
 
-To build the final HTML book type
+To build and publish the book type
 
     rake publish
 
-which will generate the final [HTML book] which is served on the web via GHPages as a multi-page chunked document:
+which will generate:
 
-- [`../docs/index.html`][HTML book]
+1. **The [online book] edition** — served on the web via GHPages as a multi-page chunked document:
+
+    [`../docs/index.html`][chunked book]
+
+2. **The [HTML book] edition** — for end users download, as a fully standalone single-file document:
+
+    [`../docs/download/Git-Book.html`][standalone book]
 
 The generated documents are tracked by Git, so don't include them in your commits or pull requests unless you're intentionally willing to update them.
 
@@ -425,24 +431,32 @@ There are 156 footnotes in the book.
 [gb_attribs]: ./gitbuch_custom-attributes.adoc
 [gb_fnotes]: ./gitbuch_footnotes.adoc
 
+<!-- Book Links -->
+
+[online book]: https://fossy-cats.github.io/Git-Buch_EN/ "Online book: Chunked HTML  (website link)"
+[HTML book]: https://fossy-cats.github.io/Git-Buch_EN/download/Git-Book.html "Online book: Standalone HTML file (website link)"
+[chunked book]: ../docs/index.html "Chunked HTML book (local preview)"
+[standalone book]: ../docs/download/Git-Book.html "Standalone HTML book (local preview)"
+
+    [`../docs/download/Git-Book.html`][standalone book]
+
+
 <!-- HTML Local Previews -->
 
-[HTML book]: ../docs/index.html "Local HTML Preview"
-
-[Preface]: ../docs/index.html#ch.preface "Local HTML Preview"
-[Ch1]: ../docs/index.html#ch.intro "Local HTML Preview"
-[Ch2]: ../docs/index.html#ch.basics "Local HTML Preview"
-[Ch3]: ../docs/index.html#ch.praxis "Local HTML Preview"
-[Ch4]: ../docs/index.html#ch.advanced "Local HTML Preview"
-[Ch5]: ../docs/index.html#ch.distributed-git "Local HTML Preview"
-[Ch6]: ../docs/index.html#ch.workflows "Local HTML Preview"
-[Ch7]: ../docs/index.html#ch.server "Local HTML Preview"
-[Ch8]: ../docs/index.html#ch.automation "Local HTML Preview"
-[Ch9]: ../docs/index.html#sec.git-svn-cvs "Local HTML Preview"
-[Ch10]: ../docs/index.html#ch.shell-integration "Local HTML Preview"
-[Ch11]: ../docs/index.html#ch.github "Local HTML Preview"
-[AppA]: ../docs/index.html#app.installation "Local HTML Preview"
-[AppB]: ../docs/index.html#app.git-repository-layout "Local HTML Preview"
+[Preface]: ../docs/download/Git-Book.html#ch.preface "Local HTML Preview"
+[Ch1]: ../docs/download/Git-Book.html#ch.intro "Local HTML Preview"
+[Ch2]: ../docs/download/Git-Book.html#ch.basics "Local HTML Preview"
+[Ch3]: ../docs/download/Git-Book.html#ch.praxis "Local HTML Preview"
+[Ch4]: ../docs/download/Git-Book.html#ch.advanced "Local HTML Preview"
+[Ch5]: ../docs/download/Git-Book.html#ch.distributed-git "Local HTML Preview"
+[Ch6]: ../docs/download/Git-Book.html#ch.workflows "Local HTML Preview"
+[Ch7]: ../docs/download/Git-Book.html#ch.server "Local HTML Preview"
+[Ch8]: ../docs/download/Git-Book.html#ch.automation "Local HTML Preview"
+[Ch9]: ../docs/download/Git-Book.html#sec.git-svn-cvs "Local HTML Preview"
+[Ch10]: ../docs/download/Git-Book.html#ch.shell-integration "Local HTML Preview"
+[Ch11]: ../docs/download/Git-Book.html#ch.github "Local HTML Preview"
+[AppA]: ../docs/download/Git-Book.html#app.installation "Local HTML Preview"
+[AppB]: ../docs/download/Git-Book.html#app.git-repository-layout "Local HTML Preview"
 
 <!-- upstream sources -->