Use <code> block, add docs (#3)

* Swap to encoding code block in `<code>` tags which seem more robust.
* Add more documentation.

Author: eyurtsev

docs/source/api.rst

@@ -13,8 +13,11 @@ The main **Kork** API is shown here:
 
   CodeChain
   AstPrinter
-  AbstractRetriever
-  SimpleRetriever
+  AbstractContextRetriever
+  SimpleContextRetriever
+  AbstractExampleRetriever
+  SimpleExampleRetriever
+
 
 
 Kork Interpreter 
@@ -25,6 +28,7 @@ Kork Interpreter
   InterpreterResult
   run_interpreter
   Environment
+  KorkException
 
 
 Index

docs/source/index.md

@@ -91,6 +91,7 @@ retrievers
 ```{toctree}
 :caption: Examples
 calculator
+query_analyzer
 ```
 
 ```{toctree}