[PATCH v2 2/3] myfirstcontrib: add dependency installation step

[Emily Shaffer <emilyshaffer@google.com>]

Indicate that the user needs some dependencies before the build will run
happily on their machine; this dependency list doesn't seem to be made
clear anywhere else in the project documentation. Then, so the user can
be certain any build failures are due to their code and not their
environment, perform a build on a clean checkout of 'master'. Also, move
the note about build parallelization up here, so that it appears next to
the very first build invocation in the tutorial.

Reported-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 Documentation/MyFirstContribution.txt | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/Documentation/MyFirstContribution.txt b/Documentation/MyFirstContribution.txt
index 12b7256454..5ce94e077c 100644
--- a/Documentation/MyFirstContribution.txt
+++ b/Documentation/MyFirstContribution.txt
@@ -38,6 +38,26 @@ $ git clone https://github.com/git/git git
 $ cd git
 ----
 
+[[dependencies]]
+=== Installing Dependencies
+
+To build Git from source, you need to have a handful of dependencies installed
+on your system. For a hint of what's needed, you can take a look at
+`INSTALL`, paying close attention to the section about Git's dependencies on
+external programs and libraries. That document mentions a way to "test-drive"
+our freshly built Git without installing; that's the method we'll be using in
+this tutorial.
+
+Make sure that your environment has everything you need by building your brand
+new clone of Git from the above step:
+
+----
+$ make
+----
+
+NOTE: The Git build is parallelizable. `-j#` is not included above but you can
+use it as you prefer, here and elsewhere.
+
 [[identify-problem]]
 === Identify Problem to Solve
 
@@ -138,9 +158,6 @@ NOTE: When you are developing the Git project, it's preferred that you use the
 `DEVELOPER` flag; if there's some reason it doesn't work for you, you can turn
 it off, but it's a good idea to mention the problem to the mailing list.
 
-NOTE: The Git build is parallelizable. `-j#` is not included above but you can
-use it as you prefer, here and elsewhere.
-
 Great, now your new command builds happily on its own. But nobody invokes it.
 Let's change that.
 
-- 
2.24.0.rc0.303.g954a862665-goog