Some more random copyediting of Hugo docs

- Change "livereload" and "live reload" to "LiveReload";
 - Add a `$ ` prompt before example command lines
   (not exhaustive, work in progress);
 - Remove unnecessary whitespace from partials;
 - Revise the blackfriday options table in overview/configuration.md
   to make it narrower.
 - Manually set the language for highlight.js where appropriate
 - Rename "404" to "Custom 404 page", and remove incorrect reference
   to "homepage"
 - Credit the author of tutorials/github_pages_blog.md
   (Similar notes are necessary for other contributed pages where
    "I" am not spf13 to avoid reader confusion.)
 - Add CSS for `kbd` and `table` etc. to css/style.css;
 - etc.

docs/static/css/style.css

@@ -457,3 +457,47 @@ input.gsc-search-button-v2 {
 .gsc-search-box-tools .gsc-search-box .gsc-input {
   padding-right: 1px !important;
 }
+
+/* Styled keypress from Wikipedia */
+
+kbd {
+  border: 1px solid #aaa;
+  -moz-border-radius: 0.2em;
+  -webkit-border-radius: 0.2em;
+  border-radius: 0.2em;
+  -moz-box-shadow: 0.1em 0.2em 0.2em #ddd;
+  -webkit-box-shadow: 0.1em 0.2em 0.2em #ddd;
+  box-shadow: 0.1em 0.2em 0.2em #ddd;
+  background-color: #f9f9f9;
+  background-image: -moz-linear-gradient(top, #eee, #f9f9f9, #eee);
+  background-image: -o-linear-gradient(top, #eee, #f9f9f9, #eee);
+  background-image: -webkit-linear-gradient(top, #eee, #f9f9f9, #eee);
+  background-image: linear-gradient(to bottom, #eee, #f9f9f9, #eee);
+  padding: 0.1em 0.3em;
+  font-family: inherit;
+  font-size: 0.85em;
+}
+
+/* For the table used in overview/configuration */
+
+table.table {
+  margin: 1em 0;
+}
+
+.table-bordered th,
+.table-bordered td {
+  border: 2px solid #ddd;
+  padding: 0 0.5em;
+}
+
+td.purpose-title {
+  text-align: right;
+  vertical-align: top;
+  border-right: 0;
+  padding-right: 0.5em;
+  font-weight: bold;
+}
+
+td.purpose-description {
+  border-left: 0;
+}