Finalize TypeScript implementation of TypeID (#58)

Add final tests, bump version number, change package.json appropriately.

Note that because `typeid-ts` is already taken in npm, I'm planning to
rename the directory, package and repo to `typeid-js`. But I wanted to
get in this diff in first, and then I'll do the renaming.

spec/valid.yml

@@ -17,7 +17,7 @@
 # decoding and re-encoding the id, the result is the same as the original.
 #
 # In other words, the following property should always hold:
-# random_typeid: encode(decode(random_typeid))
+# random_typeid == encode(decode(random_typeid))
 #
 # Finally, while implementations should be able to decode the values below,
 # note that not all of them are UUIDv7s. When *generating* new random typeids,