legal: include LICENSEs for data files

We depend upon data files from golang arch sub-repo and the Opcodes XML
database (behind PeachPy). This change includes their LICENSE files.

Updates #22

internal/data/dl.sh

@@ -0,0 +1,72 @@
+#!/bin/bash -ex
+
+datadir=$(dirname "${BASH_SOURCE[0]}")
+
+dl() {
+    url=$1
+    name=$(basename ${url})
+
+    mkdir -p ${datadir}
+    curl --output ${datadir}/${name} ${url}
+
+    echo "* ${url}"
+}
+
+hdr() {
+    echo "-----------------------------------------------------------------------------"
+    echo $1
+    echo "-----------------------------------------------------------------------------"
+}
+
+addlicense() {
+    repo=$1
+    file=$2
+
+    tmp=$(mktemp)
+    mv ${file} ${tmp}
+
+    # append to LICENSE file
+    {
+        hdr "${repo} license"
+        echo
+        cat ${tmp}
+        echo
+    } >> ${datadir}/LICENSE
+
+    # include in readme
+    echo "### License"
+    echo '```'
+    cat ${tmp}
+    echo '```'
+
+    rm ${tmp}
+}
+
+{
+    echo '# data'
+    echo 'Underlying data files for instruction database.'
+    echo
+
+    # golang/arch x86 csv
+    repo='golang/arch'
+    sha='5a4828bb704534b8a2fa09c791c67d0fb372f472'
+
+    echo "## ${repo}"
+    echo 'Files downloaded:'
+    echo
+    dl https://raw.githubusercontent.com/${repo}/${sha}/x86/x86.v0.2.csv
+    dl https://raw.githubusercontent.com/${repo}/${sha}/LICENSE
+    addlicense ${repo} ${datadir}/LICENSE
+
+    # opcodes
+    repo='Maratyszcza/Opcodes'
+    sha='6e2b0cd9f1403ecaf164dea7019dd54db5aea252'
+
+    echo "## ${repo}"
+    echo 'Files downloaded:'
+    echo
+    dl https://raw.githubusercontent.com/${repo}/${sha}/opcodes/x86_64.xml
+    dl https://raw.githubusercontent.com/${repo}/${sha}/license.rst
+    addlicense ${repo} ${datadir}/license.rst
+
+} > ${datadir}/README.md