Feature matrix improvements (microsoft#509)

### Motivation and Context
With the official publishing of the Python Semantic Kernel, we should be
informing the public of feature parity between Python and C#. Python is
currently playing catch up.


### Description
Removed the FEATURE_PARITY.md file from the python directory and added a
FEATURE_MATRIX.md file to the top level of the repo. The main REAME.md
now links to this file. Added a stronger breakdown of features that we
are tracking for SK.

FEATURE_MATRIX.md

@@ -0,0 +1,65 @@
+# Kernel Feature Matrix by Language
+
+## AI Services
+| | C# | Python | Notes |
+|---|---|---|---|                   
+| TextGeneration                    | ✅ | ✅ | Example: Text-Davinci-003 |
+| TextEmbeddings                    | ✅ | ✅ | Example: Text-Embeddings-Ada-002 |
+| ChatCompletion                    | ✅ | ❌ | Example: GPT4, Chapt-GPT |
+| Image Generation                  | ✅ | ❌ | Example: Dall-E |
+
+## AI Service Endpoints
+| | C# | Python | Notes |
+|---|---|---|---|                   
+| OpenAI                            | ✅ | ✅ | |
+| AzureOpenAI                       | ✅ | ✅ | |
+| Hugging Face                      | ✅ | ❌ | Coming soon to Python - both native and web endpoint support | 
+| Custom                            | ✅ | ❌ | Requires the user to define the service schema in their application |
+
+## Tokenizers
+| | C# | Python | Notes |
+|---|---|---|---|         
+| GPT2                              | ✅ | 🔄 | Can be manually added to Python via `pip install transformers` |
+| GPT3                              | ✅ | ❌ | | 
+| tiktoken                          | 🔄 | ❌ | Coming soon to Python and C#. Can be manually added to Python via `pip install tiktoken` |         
+
+## Core Skills
+| | C# | Python | Notes |
+|---|---|---|---|                   
+| TextMemorySkill                   | ✅ | ✅ | |
+| PlannerSkill                      | ✅ | 🔄 | |
+| ConversationSummarySkill          | ✅ | ❌ | | 
+| FileIOSkill                       | ✅ | ✅ | |
+| HttpSkill                         | ✅ | ❌ | |
+| MathSkill                         | ✅ | ❌ | |
+| TextSkill                         | ✅ | ✅ | |
+| TimeSkill                         | ✅ | ✅ | |
+
+## Connectors and Skill Libraries  
+| | C# | Python | Notes |
+|---|---|---|---|                   
+| Qdrant (Memory)                   | ✅ | ❌ | Vector optimized | 
+| ChromaDb (Memory)                 | ❌ | 🔄 | |
+| Milvus (Memory)                   | ❌ | ❌ | Vector optimized |
+| Pinecone (Memory)                 | ❌ | ❌ | Vector optimized |
+| Weaviate (Memory)                 | ❌ | ❌ | Vector optimized |
+| CosmosDB (Memory)                 | ✅ | ❌ | CosmosDB is not optimized for vector storage |
+| Sqlite (Memory)                   | ✅ | ❌ | Sqlite is not optimized for vector storage |
+| Azure Cognitive Search            | ❌ | ❌ | |
+| MsGraph                           | ✅ | ❌ | Contains connectors for OneDrive, Outlook, ToDos, and Organization Hierarchies |
+| Document Skills                   | ✅ | ❌ | Currently only supports Word documents |
+| OpenAPI                           | ✅ | ❌ | |
+| Web Skills                        | ✅ | ❌ | |
+
+# Design Choices
+
+The overall architecture of the core kernel is consistent across Python and C#,
+however, the code should follow common paradigms and style of each language.
+
+During the initial development phase, many Python best practices have been ignored
+in the interest of velocity and feature parity. The project is now going through
+a refactoring exercise to increase code quality.
+
+To make the Kernel as lightweight as possible, the core pip package should have
+a minimal set of external dependencies. On the other hand, the SDK should not
+reinvent mature solutions already available, unless of major concerns.

README.md

@@ -56,6 +56,8 @@ Semantic Kernel is available to explore AI and build apps with C# and Python:
 </div>
 <br/>
 
+See the [Feature Matrix](FEATURE_MATRIX.md) to see a breakdown of feature parity between C# and Python.
+
 The quickest way to get started with the basics is to get an API key
 (OpenAI or Azure OpenAI)
 and to run one of the C# or Python console applications/scripts: