Add BCE temporal tags to all documents; add temporal-dating steering doc

trade-routes/amber-road.md

@@ -7,7 +7,7 @@
 The Amber Road was an ancient trade route connecting the Baltic Sea coast to the Mediterranean, primarily transporting amber from northern Europe to the civilizations of Greece, Rome, and Egypt.
 
 ## Key Facts
-- Period: ~3000 BCE – Roman era
+- Period: ~3000 BCE – Roman era @t[=000 BCE]
 - Key good: Baltic amber (fossilized tree resin)
 - Northern terminus: Baltic coast (modern Poland, Lithuania)
 - Southern terminus: Adriatic (Aquileia), Greece, Egypt
@@ -18,7 +18,7 @@ The Amber Road was an ancient trade route connecting the Baltic Sea coast to the
 - Connected to Mediterranean trade networks at the Adriatic [^1]
 
 ## Significance
-- Baltic amber found in Mycenaean shaft graves (~1600 BCE) and Egyptian tombs
+- Baltic amber found in Mycenaean shaft graves (~1600 BCE) and Egyptian tombs @t[~1600 BCE]
 - Romans valued amber highly; Nero sent an expedition to the Baltic
 - Facilitated cultural exchange between northern and southern Europe [^2]
 

trade-routes/incense-route.md

@@ -20,7 +20,7 @@ The Incense Route was a network of trade paths connecting the Arabian Peninsula
 ## Key Players
 - Nabataeans: Controlled the northern segment from Petra; grew wealthy as middlemen
 - Kingdom of Saba (Sheba): Controlled production in southern Arabia
-- Romans: Attempted to conquer Arabia Felix under Aelius Gallus (25 BCE) but failed [^2]
+- Romans: Attempted to conquer Arabia Felix under Aelius Gallus (25 BCE) but failed @t[=25 BCE] [^2]
 
 ## Decline
 Declined after the Romans discovered monsoon wind patterns enabling direct sea trade with India (~1st century CE), bypassing overland routes.

trade-routes/silk-road.md

@@ -7,7 +7,7 @@
 The Silk Road was a network of overland trade routes connecting China to the Mediterranean world, facilitating the exchange of goods, ideas, religions, and technologies for over 1,500 years.
 
 ## Key Facts
-- Period: ~130 BCE – ~1450 CE (ancient period focus: ~130 BCE – ~400 CE)
+- Period: ~130 BCE – ~1450 CE (ancient period focus: ~130 BCE – ~400 CE) @t[130 BCE..1450]
 - Length: ~6,400 km (main route)
 - Named by: Ferdinand von Richthofen (1877)
 - Key goods: Silk, spices, gold, glass, horses, precious stones
@@ -25,7 +25,7 @@ The Silk Road was a network of overland trade routes connecting China to the Med
 - Diseases also spread, possibly including plague [^2]
 
 ## Key Periods
-- Han dynasty (206 BCE – 220 CE): Zhang Qian's missions opened the route (~130 BCE)
+- Han dynasty (206 BCE – 220 CE): Zhang Qian's missions opened the route (~130 BCE) @t[206 BCE..220]
 - Kushan Empire (1st–3rd century CE): Facilitated trade across Central Asia
 - Roman demand for Chinese silk drove trade westward