pkg download command and patches

assets/var/gnu/tcpdump.md

@@ -0,0 +1,13 @@
+tcpdump
+=
+https://www.tcpdump.org/release/tcpdump-4.99.6.tar.xz
+
+``` sh *** build ***
+./configure --prefix=$pkgpath
+make -j$(nproc)
+make install
+```
+
+``` cfg *** build deps ***
+libpcap
+```