Consistently use "sentence case" style

Try to be more consistent in how we capitalize things. Both the "Title
Case" and "Sentence case" styles are popular, so either would work.
Google and Mozilla both prefer "Sentence case", so let's follow them.

docs/EMBEDDING.md

@@ -1,4 +1,4 @@
-# Embedding and Deploying noVNC Application
+# Embedding and deploying noVNC application
 
 This document describes how to embed and deploy the noVNC application, which
 includes settings and a full user interface. If you are looking for
@@ -71,8 +71,8 @@ query string. Currently the following options are available:
 * `logging` - The console log level. Can be one of `error`, `warn`, `info` or
   `debug`.
 
-## HTTP Serving Considerations
-### Browser Cache Issue
+## HTTP serving considerations
+### Browser cache issue
 
 If you serve noVNC files using a web server that provides an ETag header, and
 include any options in the query string, a nasty browser cache issue can bite
@@ -84,7 +84,7 @@ to always revalidate cached files using conditional requests. The correct
 semantics are achieved via the (confusingly named) `Cache-Control: no-cache`
 header that needs to be provided in the web server responses.
 
-### Example Server Configurations
+### Example server configurations
 
 Apache: