docs: update README with sections and DB information

Signed-off-by: Alfredo Deza <adeza@anchore.com>

README.md

@@ -1,3 +1,71 @@
 # grype
 
 A vulnerability scanner for container images and filesystems
+
+
+## Getting started
+
+### Installation
+
+### Scanning Images
+
+### Scanning local paths
+
+## Developing
+
+There are a few useful things to know before diving into the codebase. This project depends on a few things being available like a vulnerability database, which you might want to create manually instead of retrieving a released version.
+
+
+### Inspecting the database
+
+The currently supported database provider is Sqlite3. Install `sqlite3` in your system and ensure that the `sqlite3` executable is available in your path. Ask `grype` about the location of the database, which will be different depending on the operating system:
+
+```
+$ go run main.go db status
+Location:  /Users/alfredo/Library/Caches/grype/db
+Built:  2020-07-31 08:18:29 +0000 UTC
+Current DB Version:  1
+Require DB Version:  1
+Status: Valid
+```
+
+In this case (OSX), the database is located in the user's home directory. To verify the database filename, list that path:
+
+```
+$ ls -alh  /Users/alfredo/Library/Caches/grype/db
+total 445392
+drwxr-xr-x  4 alfredo  staff   128B Jul 31 09:27 .
+drwxr-xr-x  3 alfredo  staff    96B Jul 31 09:27 ..
+-rw-------  1 alfredo  staff   139B Jul 31 09:27 metadata.json
+-rw-r--r--  1 alfredo  staff   217M Jul 31 09:27 vulnerability.db
+```
+
+Next, open the `vulnerability.db` with `sqlite3`:
+
+```
+$ sqlite3 /Users/alfredo/Library/Caches/grype/db/vulnerability.db
+```
+
+To make the reporting from Sqlite3 easier to read, enable the following:
+
+```
+sqlite> .mode column
+sqlite> .headers on
+```
+
+List the tables:
+
+```
+sqlite> .tables
+id                      vulnerability           vulnerability_metadata
+```
+
+In this example you retrieve a specific vulnerability from the `nvd` namespace:
+
+```
+sqlite> select * from vulnerability where (namespace="nvd" and package_name="libvncserver") limit 1;
+id             record_source  package_name  namespace   version_constraint  version_format  cpes                                                         proxy_vulnerabilities
+-------------  -------------  ------------  ----------  ------------------  --------------  -----------------------------------------------------------  ---------------------
+CVE-2006-2450                 libvncserver  nvd         = 0.7.1             unknown         ["cpe:2.3:a:libvncserver:libvncserver:0.7.1:*:*:*:*:*:*:*"]  []
+```
+