docs: fix way too small figures in pdf

docs/conf.py

@@ -207,6 +207,7 @@ latex_logo = '_static/logo.pdf'
 latex_elements = {
     'papersize': 'a4paper',
     'pointsize': '10pt',
+    'figure_align': 'H',
 }
 
 # For "manual" documents, if this is true, then toplevel headings are parts,

docs/internals.rst

@@ -27,6 +27,8 @@ chunk is checked against the :ref:`chunks cache <cache>`, which is a
 hash-table of all chunks that already exist.
 
 .. figure:: internals/structure.png
+    :figwidth: 100%
+    :width: 100%
 
     Layers in Borg. On the very top commands are implemented, using
     a data access layer provided by the Archive and Item classes.

docs/internals/data-structures.rst

@@ -204,8 +204,9 @@ commit is written to the new segment. Then, the old segment is deleted
 A simplified example (excluding conditional compaction and with simpler
 commit logic) showing the principal operation of compaction:
 
-.. figure::
-    compaction.png
+.. figure:: compaction.png
+    :figwidth: 100%
+    :width: 100%
 
 (The actual algorithm is more complex to avoid various consistency issues, refer to
 the ``borg.repository`` module for more comments and documentation on these issues.)
@@ -288,6 +289,8 @@ by their chunk ID, which is cryptographically derived from their contents.
 More on how this helps security in :ref:`security_structural_auth`.
 
 .. figure:: object-graph.png
+    :figwidth: 100%
+    :width: 100%
 
 .. _manifest:
 
@@ -640,6 +643,8 @@ and both are stored in the chunk. Encryption and MAC use two different keys.
 Each chunk consists of ``TYPE(1)`` + ``MAC(32)`` + ``NONCE(8)`` + ``CIPHERTEXT``:
 
 .. figure:: encryption.png
+    :figwidth: 100%
+    :width: 100%
 
 In AES-CTR mode you can think of the IV as the start value for the counter.
 The counter itself is incremented by one after each 16 byte block.