instruction updates

Author: tawheeler

Diff for: README.md

@@ -30,6 +30,19 @@ sudo python setup.py install
 cd ..
 ```
 
+Compile the lexer:
+```
+cd lexer
+sudo python setup.py install
+cd ..
+```
+
+Install the PGFPlots.jl package:
+```julia
+using Pkg
+Pkg.add("PGFPlots")
+```
+
 Install `pdf2svg`, which is used by PGFPlots (we assume Ubuntu - other operating systems may install pdf2svg differently):
 ```
 sudo apt-get install pdf2svg
@@ -40,7 +53,7 @@ Install [pgfplots](https://ctan.org/pkg/pgfplots).
 Install the Weave.jl package:
 ```julia
 using Pkg
-Pkg.add("Weave.jl")
+Pkg.add("Weave")
 ```
 
 Update the texlive manager and install pythontex:

Diff for: book.pdf

@@ -81,7 +81,7 @@ \section{Using Julia}
 	\end{tikzpicture}
 	\caption{
 		\label{fig:sample_tikzpicture}
-		A figure made using the \texttt{tikzpicture} environment.
+		A figure made using a \texttt{tikzpicture} environment.
 	}
 \end{figure}
 

Diff for: chapter/introduction.tex

@@ -1,14 +1,5 @@
 # Any imports you need go here.
 using PGFPlots
-using TikzPictures
-using LinearAlgebra
-using Distributions
-using Random
-using StatsBase
-using Vec
-using Printf
-
-import Base: rand, <, ==
 
 include("all_algorithm_blocks.jl")