[source] target/sdk: update README.SDK to explain dependency handling

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=d4abe72cce2abd39e0f0f013a98d8b40025b58f6

commit d4abe72cce2abd39e0f0f013a98d8b40025b58f6
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Mon Aug 1 11:55:53 2016 +0200

    target/sdk: update README.SDK to explain dependency handling
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 target/sdk/files/README.SDK | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/target/sdk/files/README.SDK b/target/sdk/files/README.SDK
index e46f0c5..6f04f94 100644
--- a/target/sdk/files/README.SDK
+++ b/target/sdk/files/README.SDK
@@ -4,4 +4,8 @@ having to compile your own toolchain or any of the libraries
 included with LEDE.
 
 To use it, just put your buildroot-compatible package directory
-in the subdir 'package/' and run 'make' from this directory.
+(including its dependencies) in the subdir 'package/' and run
+'make' from this directory.
+
+To make dependency handling easier, you can use ./scripts/feeds
+to install any core package that you need