Merge branch 'feature/readme'. Closes #52.

- README corrections (@bhive01, #52).

README.Rmd

@@ -35,7 +35,7 @@ You can create a new tibble from vectors that represent the columns with `data_f
 data_frame(x = 1:5, y = 1, z = x ^ 2 + y)
 ```
 
-`data_frame()` is does much less than `data.frame()`: it never changes the type of the inputs (e.g. it never converts strings to factors!), it never changes the names of variabels, and it never creates `row.names()`. You can read more about these features in the vignette, `vignette("tibble")`.
+`data_frame()` does much less than `data.frame()`: it never changes the type of the inputs (e.g. it never converts strings to factors!), it never changes the names of variables, and it never creates `row.names()`. You can read more about these features in the vignette, `vignette("tibble")`.
 
 You can define a tibble row-by-row with `frame_data()`:
 
@@ -58,7 +58,7 @@ library(nycflights13)
 flights
 ```
 
-Tibles are strict about subsetting. If you try and access a variable that does not, you'll get an error:
+Tibbles are strict about subsetting. If you try to access a variable that does not exist, you'll get an error:
 
 ```{r, error = TRUE}
 flights$yea

README.md

@@ -47,7 +47,7 @@ data_frame(x = 1:5, y = 1, z = x ^ 2 + y)
 #> 5     5     1    26
 ```
 
-`data_frame()` is does much less than `data.frame()`: it never changes the type of the inputs (e.g. it never converts strings to factors!), it never changes the names of variabels, and it never creates `row.names()`. You can read more about these features in the vignette, `vignette("tibble")`.
+`data_frame()` is does much less than `data.frame()`: it never changes the type of the inputs (e.g. it never converts strings to factors!), it never changes the names of variables, and it never creates `row.names()`. You can read more about these features in the vignette, `vignette("tibble")`.
 
 You can define a tibble row-by-row with `frame_data()`:
 
@@ -94,7 +94,7 @@ flights
 #>   (dbl), distance (dbl), hour (dbl), minute (dbl).
 ```
 
-Tibles are strict about subsetting. If you try and access a variable that does not, you'll get an error:
+Tibbles are strict about subsetting. If you try to access a variable that does not exist, you'll get an error:
 
 ``` r
 flights$yea