add days per category

#5

src/work-calendar.cpp

@@ -4,6 +4,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <hydrogen.h>
+#include <inttypes.h>
 
 #include "inter.h"
 #include "inter-bold.h"
@@ -635,7 +636,13 @@ void per_frame(){
                         category.editing = false;
                     }
                 } else {
-                    ImGui::Text("%s", category.name);
+                    uint64_t num_days_this_year = 0;
+                    for (size_t j = 0; j < num_categorized_days; j++) {
+                        if (categorized_days[j].category == i && categorized_days[j].year == year) {
+                            num_days_this_year++;
+                        }
+                    }
+                    ImGui::Text("%s (%" PRIu64 ")", category.name, num_days_this_year);
                 }
 
                 ImGui::TableSetColumnIndex(2);