heatmap_matrix: Get the similarity matrix
In cristianmejia00/heatmaps3: Creates heatmpas form lists of keywords

A similarity matrix based on cosine similarity

1 2	heatmap_matrix(x_axis_lodf, y_axis_lodf, x_label = "X", y_label = "Y", report = TRUE)

`x_axis_lodf`	a list of data frames. The first column is for the terms, the second for the value(relevance)
`y_axis_lodf`	a list of data frames. The first column is for the terms, the second for the value(relevance)
`x_label`	default to "X". a name for the values in the X axis
`y_label`	default to "Y". a name for the values in the Y axis
`report`	default to TRUE. whether to save the similarity matrix as .csv file