docs: Migrate Docsify docs into RTD

Re: #887

packages/core/python/itkwasm/docs/conf.py

@@ -8,7 +8,7 @@
 
 from datetime import date
 
-project = 'itkwasm'
+project = 'ITK-Wasm'
 copyright = f'{date.today().year}, NumFOCUS'
 author = 'Matt McCormick'
 
@@ -44,7 +44,7 @@
 html_static_path = ['_static']
 html_logo = "_static/logo-white.svg"
 html_favicon = "_static/icon/favicon.png"
-html_title = f"{project} python documentation"
+html_title = f"{project} documentation"
 
 # Furo options
 html_theme_options = {

packages/core/python/itkwasm/docs/cxx/installation.md

@@ -0,0 +1,10 @@
+# Installation
+
+Building WebAssembly pipelines is driven by the `itk-wasm` Node.js command line executable, which drives builds, run tests, and generates interface bindings. Install with:
+
+```sh
+npm install -g itk-wasm
+```
+
+For more information and guidance on installation, see [the tutorial
+Introduction](../tutorial/hello_world?id=introduction).

packages/core/python/itkwasm/docs/cxx/interface_types.md

@@ -0,0 +1,69 @@
+# Interface Types
+
+itk-wasm execution pipelines support the following [interface types](https://github.com/InsightSoftwareConsortium/itk-wasm/tree/main/src/core/InterfaceTypes.ts):
+
+- [TextFile](../typescript/interface_types/TextFile)
+- [BinaryFile](../typescript/interface_types/BinaryFile)
+- [TextStream](../typescript/interface_types/TextStream)
+- [BinaryStream](../typescript/interface_types/BinaryStream)
+- [Image](../typescript/interface_types/Image)
+- [Mesh](../typescript/interface_types/Mesh)
+- [PolyData](../typescript/interface_types/PolyData)
+- [JsonObject](../typescript/interface_types/JsonObject)
+
+These interfaces types are supported in the [Emscripten interface](../typescript/browser_pipelines), [WASI](https://wasi.dev/) embedding interfaces, and native or virtual [filesystem IO](../introduction/file_formats/index). They are intended to be forward-compatible with the [WebAssembly Component Model](https://github.com/WebAssembly/component-model).
+
+---
+
+The following [CLI11](https://github.com/CLIUtils/CLI11) [`itk::wasm::Pipeline`](https://github.com/InsightSoftwareConsortium/itk-wasm/tree/main/include/itkPipeline.h) components can be included in a C++ to ingest and produce these interface types. For `Input` types, use `Get()` to get the corresponding C++ object value after `ITK_WASM_PARSE_ARGS` is called. For `Output` types, use `Set(value)` to output the value before `main` exits. For example,
+
+```cpp
+#include "itkPipeline.h"
+#include "itkInputTextStream.h"
+#include "itkOutputTextStream.h"
+
+int main(argc, char * argv[])
+{
+  itk::wasm::Pipeline pipeline("test-pipeline", "A test ITK Wasm Pipeline", argc, argv);
+
+  itk::wasm::InputTextStream inputTextStream;
+  pipeline.add_option("InputText", inputTextStream,
+    "The input text")->required()->type_name("INPUT_TEXT_STREAM");
+
+  itk::wasm::OutputTextStream outputTextStream;
+  pipeline.add_option("OutputText", outputTextStream,
+    "The output text")->required()->type_name("OUTPUT_TEXT_STREAM");
+
+
+  ITK_WASM_PARSE(pipeline);
+
+
+  const std::string inputTextStreamContent{ std::istreambuf_iterator<char>(inputTextStream.Get()),
+                                            std::istreambuf_iterator<char>() };
+
+  outputTextStream.Get() << inputTextStreamContent;
+}
+```
+
+<dl>
+  <dt><b><code>itk::wasm::InputTextStream</code></b><dt><dd>A string. To reader this data type in C++, using the resulting  <a href="https://www.cplusplus.com/reference/istream/istream/">std::istream</a>.</dd>
+</dl>
+
+*todo: document remaining CLI11 input and output classes.*
+
+For binding generation, set the `type_name` an the options accordingly. The type names are:
+
+- `INPUT_TEXT_FILE`
+- `OUTPUT_TEXT_FILE`
+- `INPUT_BINARY_FILE`
+- `OUTPUT_BINARY_FILE`
+- `INPUT_TEXT_STREAM`
+- `OUTPUT_TEXT_STREAM`
+- `INPUT_BINARY_STREAM`
+- `OUTPUT_BINARY_STREAM`
+- `INPUT_IMAGE`
+- `OUTPUT_IMAGE`
+- `INPUT_MESH`
+- `OUTPUT_MESH`
+- `INPUT_POLYDATA`
+- `OUTPUT_POLYDATA`