README.md: Update to include building stdplusHEADmaster

There is a new dependency on stdplus library, need to include the steps
on installing the library in the README.md.

Resolves: openbmc/phosphor-ipmi-flash#3
Signed-off-by: Brandon Kim <brandonkim@google.com>
Change-Id: I14822b65a5e7890458f974acf0bdd71016b0dd99

1 files changed, 12 insertions, 0 deletions

diff --git a/README.md b/README.md
index 7a5dde1..10e69ae 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,18 @@ make
 make install
 ```
 
+#### Building stdplus
+
+Check out the [stdplus source](https://github.com/openbmc/stdplus).
+
+Then run these commands in the source directory.
+
+```
+meson setup -Dexamples=false -Dtests=disabled builddir
+ninja -C builddir
+ninja -C builddir install
+```
+
 #### Building burn_my_bmc (the host-tool)
 
 Check out the [phosphor-ipmi-flash source](https://github.com/openbmc/phosphor-ipmi-flash).