submodules: Add maddy markdown parser (header-only library)

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "submodules/qssb.h"]
 	path = submodules/qssb.h
 	url = https://gitea.quitesimple.org/crtxcr/qssb.h.git
+[submodule "submodules/maddy"]
+	path = submodules/maddy
+	url = https://github.com/progsource/maddy

Makefile

@@ -3,7 +3,7 @@
 CXXFLAGS=-std=c++17 -O0 -g -no-pie -pipe -MMD -Wall -Wextra
 RELEASE_CXXFLAGS=-std=c++17 -O3 -pipe -MMD -Wall -Wextra
 LDFLAGS=-lsqlite3 -lpthread -lcrypto -lstdc++fs -lseccomp
-INCLUDEFLAGS=-I submodules/sqlitemoderncpp/hdr -I submodules/cpp-httplib -I submodules/qssb.h
+INCLUDEFLAGS=-I submodules/sqlitemoderncpp/hdr -I submodules/cpp-httplib -I submodules/qssb.h -I submodules/maddy/include/
 
 CXX=g++
 

submodules/maddy

@@ -0,0 +1 @@
+Subproject commit adb1a910d4aadea09cb7b200f2ec204f61214596