make git ignore sensitive files

The Files wallet.csv paperWallet-pics.pdf paperWallet.pdf contain
private keys and should therefore not be in git
add generte-wallet.sh

My python isn't that good so i made a bash script.
it starts vanitygen (https://github.com/samr7/vanitygen)
and adds the generated adresses and keys to the wallet.csv
all parameters passed to the script are passed to vanitygen.
useful invocations:
./generate-wallet.sh 1  # adds 1 normal address
./generate-wallet.sh 1Fuu  # adds 1 address that starts with 1Fuu
./generate-wallet.sh -k 1Fuu # adds many, until you press Ctrl + C
./generate-wallet.sh -r '^1Fuu|^1Bar' # matches a regex

the balance is ____ (with escape \ for latex)
add script for generating the pdf

creates the pdf, all latex generted stuff is kept in a seperate folder.
also echos the command to shred the sensitive files.
modified gitignore accordingly
change readme for the changes from e38f 1850 6da8
authors and new README