Docs: Documentation update. Copyright, licensing.

- Add Copyright placement guidance
- Clarify licencing information
- Remove a small typo

Signed-off-by: Anton Komlev <anton.komlev@arm.com>
Change-Id: I4c7cd0dd5607d6e60f6d7f1e87adefcc20006ba0
diff --git a/docs/contributing/coding_guide.rst b/docs/contributing/coding_guide.rst
index 3a59a41..e9f46f9 100644
--- a/docs/contributing/coding_guide.rst
+++ b/docs/contributing/coding_guide.rst
@@ -24,7 +24,7 @@
 
 .. Warning::
 
-    Text files do not fall within these rules as they may require different formatting.``
+    Text files do not fall within these rules as they may require different formatting.
 
 ****************
 Consistent style