visidata: add installer and optional deps list

config/visidata/requirements.txt

@@ -0,0 +1,21 @@
+# Optional deps used by /Users/tabledevil/gists/config/visidata/visidatarc.
+# Install into VisiData's per-user deps dir (recommended):
+#   ./install.sh --deps
+#
+# Or manually:
+#   python -m pip install --target ~/.visidata/plugins-deps -r requirements.txt
+#
+# Core HTTP / scraping
+requests
+beautifulsoup4
+lxml
+#
+# Data parsing
+PyYAML
+#
+# DNS lookups
+dnspython
+#
+# Enrichment helpers
+mac-vendor-lookup
+virus_total_apis