Merge pull request #117 from takikawa/vlq-example-rebased

Add examples for Base64 VLQ encoding

source-map.bs

@@ -143,6 +143,22 @@ Note: The values that can be represented by the VLQ Base64 encoded are limited t
 means that values exceeding 32-bits are invalid and implementations may reject
 them. The sign bit is counted towards the limit, but the continuation bits are not.
 
+<div class="example">
+The string `"iB"` represents a [=Base64 VLQ=] with two digits. The first digit
+`"i"` encodes the bit pattern `0x100010`, which has a continuation bit of `1` (the
+VLQ continues), a sign bit of `0` (non-negative), and the value bits `0x0001`.
+The second digit `B` encodes the bit pattern `0x000001`, which has a continuation
+bit of `0`, no sign bit, and value bits `0x00001`. The decoding of this VLQ string
+is the number 17.
+</div>
+
+<div class="example">
+The string `"V"` represents a [=Base64 VLQ=] with one digit. The digit
+`"V"` encodes the bit pattern `0x010101`, which has a continuation bit of `0`
+(no continuation), a sign bit of `1` (negative), and the value bits `0x1010`.
+The decoding of this VLQ string is the number -10.
+</div>
+
 <dfn>Source Mapping URL</dfn> refers to the URL referencing
 the location of a source map from the [=Generated code=].