Rename 'xpi' to 'firefox' for better clarity

diff --git a/xpi/README.md b/firefox/README.md
similarity index 100%
rename from xpi/README.md
rename to firefox/README.md

diff --git a/xpi/chrome.manifest b/firefox/chrome.manifest
similarity index 100%
rename from xpi/chrome.manifest
rename to firefox/chrome.manifest

diff --git a/xpi/chrome/content/nav.gss.js b/firefox/chrome/content/navigator.gssEap.js
similarity index 100%
rename from xpi/chrome/content/nav.gss.js
rename to firefox/chrome/content/navigator.gssEap.js

diff --git a/xpi/data/gssweb_utils.js b/firefox/data/gssweb_utils.js
similarity index 100%
rename from xpi/data/gssweb_utils.js
rename to firefox/data/gssweb_utils.js

diff --git a/xpi/data/nav.gss.js b/firefox/data/nav.gss.js
similarity index 100%
rename from xpi/data/nav.gss.js
rename to firefox/data/nav.gss.js

diff --git a/xpi/data/navigator.gss.js b/firefox/data/navigator.gss.js
similarity index 100%
rename from xpi/data/navigator.gss.js
rename to firefox/data/navigator.gss.js

diff --git a/xpi/doc/main.md b/firefox/doc/main.md
similarity index 100%
rename from xpi/doc/main.md
rename to firefox/doc/main.md

diff --git a/xpi/lib/main.js b/firefox/lib/main.js
similarity index 100%
rename from xpi/lib/main.js
rename to firefox/lib/main.js

diff --git a/xpi/package.json b/firefox/package.json
similarity index 100%
rename from xpi/package.json
rename to firefox/package.json

diff --git a/xpi/test/test-main.js b/firefox/test/test-main.js
similarity index 100%
rename from xpi/test/test-main.js
rename to firefox/test/test-main.js