Merge pull request #340 from mattcode55/fix-106-tail-emission

Create tail emission Moneropedia entry

resources/moneropedia/tail-emission.md

+---
+layout: moneropedia
+entry: "Tail Emission"
+terms: ["Tail-Emission"]
+summary: "the block reward at the end of the emission curve"
+---
+
+### The Basics
+
+Monero block rewards will never drop to zero. Block rewards will gradually drop
+until tail emission commences at the end of May 2022. At this point, rewards
+will be fixed at 0.6 XMR per block.
+
+### Why
+
+Miners need an incentive to mine. Because of the dynamic blocksize, competition
+between miners will cause fees to decrease. If mining is not profitable due to
+a high cost and low reward, miners lose their incentive and will stop mining,
+reducing the security of the network.
+
+Tail emission ensures that a dynamic block size and fee market can develop.