Make Documentation Updates Easier and More Accurate (#1573)

I made a documentation change and noticed that the result when browsed
locally did not quite match what is seen when browsing from the web.
After some research, I found mkdocs/mkdocs#2028
That described my situation well and suggested adding an extra
javascript script to the configuration. This worked exactly as desired
on my local machine. This accounts for the presence of extrajs.js
and mkdocs.yml in this request.

In addition to the display problem, "mkdocs build" generates the
documentation into a directory which is not ignored by git. I added
that directory to .gitignore as part of this request.

Finally, since I don't know how exactly the documentation makes it
to production, I made an insignificant change to one doc file as
a sanity check.

.gitignore

@@ -8,3 +8,6 @@
 *.project
 /.settings
 /.idea
+
+## mkdocs output
+/site

docs/extra/extrajs.js

@@ -0,0 +1,5 @@
+document.addEventListener("DOMContentLoaded", function() {
+  document.querySelectorAll("table").forEach(function(table) {
+    table.classList.add("docutils");
+  });
+});

docs/index.md

@@ -89,7 +89,7 @@ php vendor/phpoffice/phpspreadsheet/samples/Basic/01_Simple.php
 
 ## Learn by documentation
 
-For more in-depth documentation, you may read about an [overview of the
+For more documentation in depth, you may read about an [overview of the
 architecture](./topics/architecture.md),
 [creating a spreadsheet](./topics/creating-spreadsheet.md),
 [worksheets](./topics/worksheets.md),

mkdocs.yml

@@ -5,3 +5,5 @@ edit_uri: edit/master/docs/
 theme: readthedocs
 extra_css:
     - extra/extra.css
+extra_javascript:
+    - extra/extrajs.js