Add emoji examples to documentation (#74)

Closes #43

README.md

@@ -161,6 +161,35 @@ Available named colors are:
 | yellow        | #DFB317 | ![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/color_yellow.svg)       |
 | yellow_green  | #A4A61D | ![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/color_yellow_green.svg) |
 
+### Emojis
+
+It is possible to use emoji characters in badge labels and values. Here are some examples:
+
+![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/pipeline_frown.svg)
+![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/pipeline_smile.svg)
+![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/documentation_link.svg)
+![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/pypi_link.svg)
+
+These files were created by using the **actual** emoji character in the label/value text. For example:
+
+```python
+badge = anybadge.Badge(label="Pipeline status", value="😄")
+```
+
+There are some caveats worth mentioning:
+- The "look" of the emoji is determined by the client (Emoji characters are placed as-is into the SVG file, and are
+  rendered client-side)
+- Rendering may fail in some viewers and developer IDEs (for example, PyCharm does not render emojis in the svg viewer)
+- Emojis can have different widths, so the layout may be affected. You can use `num_label_padding_chars` and
+  `num_value_padding_chars` to fix (see below)
+
+Here are some examples to show how to use padding to fix layout:
+
+| Badge | Code                                                                 |
+| ----- |----------------------------------------------------------------------|
+| ![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/pipeline_smile.svg) | `anybadge.Badge("Pipeline status", "😄")` |
+| ![](https://cdn.rawgit.com/jongracecox/anybadge/master/examples/pipeline_smile_padding.svg) | `anybadge.Badge("Pipeline status", "😄", num_value_padding_chars=1)` |
+
 ### Semantic version support
 
 Anybadge supports semantic versions for value and threshold keys. This supports color-coded

build_examples.py

@@ -1,7 +1,10 @@
+from pathlib import Path
+
 import anybadge
 
 
-def main():
+def color_examples_table():
+    """Output the Markdown table containing color examples."""
     print(
         """
 | Color Name    | Hex     | Example |
@@ -21,5 +24,30 @@ def main():
         )
 
 
+def emoji_examples():
+    """Generate emoji example badges used in documentation."""
+    examples_dir = Path(__file__).parent / Path("examples")
+    for label, value, file, kwargs in [
+        ("Pipeline status", "😄", "pipeline_smile.svg", {}),
+        (
+            "Pipeline status",
+            "😄",
+            "pipeline_smile_padding.svg",
+            {"num_value_padding_chars": 1},
+        ),
+        ("Pipeline status", "😟", "pipeline_frown.svg", {"default_color": "Red"}),
+        ("🔗", "Documentation", "documentation_link.svg", {}),
+        ("🔗", "PyPi", "pypi_link.svg", {}),
+    ]:
+        anybadge.Badge(label=label, value=value, **kwargs).write_badge(
+            examples_dir / Path(file), overwrite=True
+        )
+
+
+def main():
+    color_examples_table()
+    emoji_examples()
+
+
 if __name__ == "__main__":
     main()