Update README

Author: mbostock

CHANGELOG.md

@@ -97,7 +97,7 @@ Plot.plot({
 
 See [Plot: Axes](https://observablehq.com/@observablehq/plot-axes) for more examples, including the new _both_ **axis** option to repeat axes on both sides of the plot, dashed grid lines via the **strokeDasharray** option, data-driven tick placement, and layering axes to show hierarchical time intervals (years, months, weeks).
 
-Marks can now declare default margins via the **marginTop**, **marginRight**, **marginBottom**, and **marginLeft** options, and the **margin** shorthand. For each side, the maximum corresponding margin across marks becomes the plot’s default. While most marks default to zero margins (because they are drawn inside the chart area), Plot‘s axis mark provides default margins depending on their anchor. The facet margin options (*e.g.*., facet.**marginRight**) now correctly affect the positioning of the *x* and *y* axis labels.
+Marks can now declare default margins via the **marginTop**, **marginRight**, **marginBottom**, and **marginLeft** options, and the **margin** shorthand. For each side, the maximum corresponding margin across marks becomes the plot’s default. While most marks default to zero margins (because they are drawn inside the chart area), Plot‘s axis mark provides default margins depending on their anchor. The facet margin options (*e.g.*, facet.**marginRight**) now correctly affect the positioning of the *x* and *y* axis labels.
 
 The new [*mark*.**facetAnchor**](#facetanchor) mark option controls the facets in which the mark will appear when faceting. It defaults to null for all marks except for axis marks, where it defaults to *top-empty* if the axis anchor is *top*, *right-empty* if anchor is *right*, *bottom-empty* if anchor is *bottom*, and *left-empty* if anchor is *left*. This ensures the proper positioning of the axes with respect to empty facets.