Minor ticks and grid lines docs

doc/python/axes.md

@@ -380,6 +380,26 @@ fig.update_layout(title_text="Apple Stock Price")
 fig.show()
 ```
 
+#### Adding minor ticks
+You can add minor ticks to an axis by specifying with the `minor` property. This takes a `dict` of properties to apply to minor ticks. 
+
+In the following example, we add minor ticks to the x-axis and then to the y-axis. For the y-axis we add ticks on the outside: `minor = {"ticks":"outside"}`. On the x-axis we've spcified some additional properties to style the minor ticks, setting the length of the ticks with `ticklen` and the color with `tickcolor`. We've also turned on grid lines for the x-axis minor ticks using `showgrid`.
+
+
+```python
+import plotly.express as px
+import pandas as pd
+
+df = px.data.tips()
+fig = px.scatter(df, x="total_bill", y="tip", color="sex")
+
+
+fig.update_xaxes(minor = {"ticklen": 6, "tickcolor": "black", "showgrid" : True})
+fig.update_yaxes(minor = {"ticks":"outside"})
+
+fig.show()
+```
+
 ### Axis lines: grid and zerolines
 
 ##### Toggling Axis grid lines
@@ -464,6 +484,19 @@ fig.update_yaxes(showgrid=True, gridwidth=1, gridcolor='LightPink')
 fig.show()
 ```
 
+By default grid lines are `solid`. Set the `griddash` property to change this style. In this example we display the x-axis grid lines as `dot`. It can also be set to `dash`, `longdash`, `dashdot`, or `longdashdot`.
+
+```python
+import plotly.express as px
+df = px.data.iris()
+
+fig = px.scatter(df, x="sepal_width", y="sepal_length", facet_col="species")
+fig.update_xaxes(showgrid=True, gridwidth=1, gridcolor='LightPink', griddash='dot')
+fig.update_yaxes(showgrid=True, gridwidth=1, gridcolor='LightPink')
+
+fig.show()
+```
+
 ##### Styling zero lines
 
 The width and color of axis zero lines are controlled by the `zerolinewidth` and `zerolinecolor` axis properties.