Fix some more typos (tidymodels#313)

* Fix typo. Closes tidymodels#308.

* Fix typo. Closes tidymodels#310.

* Fix grammar. Closes tidymodels#312.

08-feature-engineering.Rmd

@@ -484,7 +484,7 @@ The `tidy()` method, when called with the recipe object, gives a summary of the
 tidy(ames_rec)
 ```
 
-This result can be helpful for identifying individual steps, perhaps to then be able to execute the `tidy()` method on one specific steps.  
+This result can be helpful for identifying individual steps, perhaps to then be able to execute the `tidy()` method on one specific step.  
 
 We can specify the `id` argument in any step function call; otherwise it is generated using a random suffix. Setting this value can be helpful if the same type of step is added to the recipe more than once. Let's specify the `id` ahead of time for `step_other()`, since we'll want to `tidy()` it:
 

11-comparing-models.Rmd

@@ -227,7 +227,7 @@ where
 
  * $\beta_1$ is the change in mean $R^2$ when interactions are added to the basic linear model,
 
- * $\beta_2$ is the change in mean $R^2$ between the basic linear model and the random forest model. 
+ * $\beta_2$ is the change in mean $R^2$ between the basic linear model and the random forest model, and 
 
  * $\beta_3$ is the change in mean $R^2$ between the basic linear model and one with interactions and splines. 
 

15-workflow-sets.Rmd

@@ -217,7 +217,7 @@ no_pre_proc <-
 no_pre_proc
 ```
 
-Finally, the set that uses nonlinear terms and interactions with the appropriate models are assembled: 
+Finally, we assemble the set that uses nonlinear terms and interactions with the appropriate models: 
 
 ```{r workflow-sets-quad}
 with_features <-