Add link to requirement strings explanation in the manifest.md doc

diff --git a/src/doc/manifest.md b/src/doc/manifest.md
index 08d0016e8fb43516456e593c2d50fa629a3e5897..1e0197a07d8b778856d86412a537cb0a8812db1d 100644 (file)
--- a/src/doc/manifest.md
+++ b/src/doc/manifest.md
@@ -132,6 +132,8 @@ hammer = "0.5.0"
 color = "0.6.0"
 ```
 
+The syntax of the requirement strings is described in the [crates.io guide](crates-io.html#using-crates.io-based-crates).
+
 Platform-specific dependencies take the same format, but are listed under the
 `target.$triple` section: