Fix xref description of shapes

[archmoj]

@plotly/plotly_js

[alexcjohnson]

Oh hmm, for shapes actually I don't think either of these is true, despite xref containing this text for 6 years! See shapes.json:

plotly.js/test/image/mocks/shapes.json

Lines 28 to 32 in b194d8c

	{"layer":"below","x0":0.1,"x1":0.4,"y0":1.5,"y1":20,"opacity":0.5,"fillcolor":"#f00","line":{"width":8,"color":"#008","dash":"dashdot"}},
	{"path":"M0.5,3C0.5,9 0.9,9 0.9,3C0.9,1 0.5,1 0.5,3ZM0.6,4C0.6,5 0.66,5 0.66,4ZM0.74,4C0.74,5 0.8,5 0.8,4ZM0.6,3C0.63,2 0.77,2 0.8,3Z","fillcolor":"#fd2","line":{"width":1,"color":"black"}},
	{"layer":"below","xref":"x2","yref":"y2","type":"circle","x0":"2000-01-01 02","x1":"2000-01-01 08:30:33.456","y0":0.1,"y1":0.9,"fillcolor":"rgba(0,0,0,0.5)","line":{"color":"rgba(0,255,0,0.5)", "width":5}},
	{"xref":"x2","yref":"y2","path":"M2000-01-01_11:20:45.6,0.2Q2000-01-01_10:00,0.85 2000-01-01_21,0.8Q2000-01-01_22:20,0.15 2000-01-01_11:20:45.6,0.2Z","fillcolor":"rgb(151,73,58)"},
	{"xref":"x2","yref":"y2","type":"line","x0":"2000-01-01 11:00","x1":"2000-01-01 09:00","y0":"b","y1":"a","line":{"color":"#006","width":3}},

The first 2 have a log y axis, and the values are as data. The next two have date x axis, and the values are date strings (with an underscore between date and time for path shapes)

But it is true for annotations on log axes only that you need to take the log of the desired position. See annotations_autorange.json where y: 2 anchors to data value 100:

plotly.js/test/image/mocks/annotations-autorange.json

Lines 72 to 76 in b194d8c

	{
	"xref":"x2","yref":"y2","text":"From left","y":2,"ax":-17,"ay":0,"x":"2001-01-01",
	"xanchor": "right", "yanchor": "top", "textangle": 35, "bordercolor": "#444",
	"xshift": 10
	},

[alexcjohnson]

💃