Populate more metadata in compiler and runtime Python packages. (iree-org#19118)

This will add more content to
https://pypi.org/project/iree-base-compiler/ and
https://pypi.org/project/iree-base-runtime/. We can also add more text
to the README files or use the repository root README instead.

Docs I followed:

* https://packaging.python.org/en/latest/specifications/core-metadata/
*
https://packaging.python.org/en/latest/specifications/well-known-project-urls/#well-known-project-urls

Author: ScottTodd

compiler/bindings/python/iree/compiler/README.md

@@ -0,0 +1,3 @@
+# IREE Python Compiler API
+
+This package provides an API for compiling IREE binaries from common input formats.

compiler/setup.py

@@ -414,6 +414,20 @@ def find_git_submodule_revision(submodule_path):
 )
 print(f"Found compiler packages: {packages}")
 
+with open(
+    os.path.join(
+        IREE_SOURCE_DIR,
+        "compiler",
+        "bindings",
+        "python",
+        "iree",
+        "compiler",
+        "README.md",
+    ),
+    "rt",
+) as f:
+    README = f.read()
+
 custom_package_suffix = os.getenv("IREE_COMPILER_CUSTOM_PACKAGE_SUFFIX", "")
 custom_package_prefix = os.getenv("IREE_COMPILER_CUSTOM_PACKAGE_PREFIX", "")
 
@@ -422,8 +436,9 @@ def find_git_submodule_revision(submodule_path):
     version=f"{PACKAGE_VERSION}",
     author="IREE Authors",
     author_email="[email protected]",
-    description="IREE Compiler API",
-    long_description="",
+    description="IREE Python Compiler API",
+    long_description=README,
+    long_description_content_type="text/markdown",
     license="Apache-2.0",
     classifiers=[
         "Development Status :: 3 - Alpha",
@@ -435,6 +450,11 @@ def find_git_submodule_revision(submodule_path):
         "Programming Language :: Python :: 3.12",
         "Programming Language :: Python :: 3.13",
     ],
+    project_urls={
+        "homepage": "https://iree.dev/",
+        "repository": "https://github.com/iree-org/iree",
+        "documentation": "https://iree.dev/reference/bindings/python/",
+    },
     ext_modules=[
         CMakeExtension("iree.compiler._mlir_libs._mlir"),
         CMakeExtension("iree.compiler._mlir_libs._ireeDialects"),

runtime/setup.py

@@ -539,7 +539,11 @@ def populate_built_package(abs_dir):
         "Programming Language :: Python :: 3.12",
         "Programming Language :: Python :: 3.13",
     ],
-    url="https://github.com/iree-org/iree",
+    project_urls={
+        "homepage": "https://iree.dev/",
+        "repository": "https://github.com/iree-org/iree",
+        "documentation": "https://iree.dev/reference/bindings/python/",
+    },
     python_requires=">=3.9",
     ext_modules=(
         [