feat: ✨ add possibility to return example path (#29)

# Description

@lwjohnst86 You will be happy (I think) to hear that I find a use case
for `Example.<name>.path` in our docs. Currently we write

```py
!uv run seedcase-flower view {so.Example.flora.address.value}
```

which would be slightly more convenient as

```py
!uv run seedcase-flower view {so.Example.flora.path}
```

However, the bigger win that I think justifies having this attribute is
that instead of

```py
from pathlib import Path

print(
    '```json',
    Path(so.Example.flora.address.value).read_text(),
    '```',
    sep='\n'
)
```

we can simply write

```py
print(
    '```json',
    so.Example.flora.path.read_text(),
    '```',
    sep='\n'
)
```

This pattern occurs a few times in the docs so I think it is worth
providing this convenience.

Needs a quick review.

## Checklist

- [x] Ran `just run-all`

Author: joelostblom

src/seedcase_soil/example_datapackage.py

@@ -2,6 +2,7 @@
 
 from enum import StrEnum
 from importlib.resources import files
+from pathlib import Path
 
 from .parse_source import Address
 
@@ -15,9 +16,14 @@ class Example(StrEnum):
     woolly = "woolly"
 
     @property
-    def address(self) -> Address:
-        """Return this example's local `Address`."""
+    def path(self) -> Path:
+        """Return this example's `Path`."""
         datapackage_path = files("seedcase_soil").joinpath(
             f"example-datapackages/{self.value}.json"
         )
-        return Address(value=str(datapackage_path), local=True)
+        return Path(str(datapackage_path))
+
+    @property
+    def address(self) -> Address:
+        """Return this example's `Address`."""
+        return Address(value=str(self.path), local=True)